diff --git a/App.xaml b/App.xaml
new file mode 100644
index 0000000..c3ddbd2
--- /dev/null
+++ b/App.xaml
@@ -0,0 +1,172 @@
+<Application x:Class="CRAWLER.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             ShutdownMode="OnMainWindowClose">
+    <Application.Resources>
+        <LinearGradientBrush x:Key="AppWindowBackgroundBrush" StartPoint="0,0" EndPoint="1,1">
+            <GradientStop Color="#FFDDE7F0" Offset="0" />
+            <GradientStop Color="#FFC7D4E2" Offset="1" />
+        </LinearGradientBrush>
+        <SolidColorBrush x:Key="AppPanelBrush" Color="#FFF1F5FA" />
+        <SolidColorBrush x:Key="AppSurfaceBrush" Color="#FFFDFEFF" />
+        <SolidColorBrush x:Key="AppAccentBrush" Color="#FF4F7498" />
+        <SolidColorBrush x:Key="AppBorderBrush" Color="#FFA7B7C8" />
+        <SolidColorBrush x:Key="AppTextBrush" Color="#FF253748" />
+        <SolidColorBrush x:Key="AppMutedTextBrush" Color="#FF697988" />
+        <SolidColorBrush x:Key="AppPrimaryButtonBrush" Color="#FF5D84A9" />
+        <SolidColorBrush x:Key="AppPrimaryButtonHoverBrush" Color="#FF6A92B8" />
+        <SolidColorBrush x:Key="AppPrimaryButtonPressedBrush" Color="#FF496B8B" />
+        <SolidColorBrush x:Key="AppButtonBrush" Color="#FFF7FAFD" />
+        <SolidColorBrush x:Key="AppButtonHoverBrush" Color="#FFE8F0F8" />
+        <SolidColorBrush x:Key="AppButtonPressedBrush" Color="#FFD7E5F2" />
+        <SolidColorBrush x:Key="AppSelectionBrush" Color="#FFD9E7F3" />
+        <SolidColorBrush x:Key="AppWarningBrush" Color="#FFB06C45" />
+        <SolidColorBrush x:Key="AppSuccessBrush" Color="#FF468468" />
+        <SolidColorBrush x:Key="AppDangerBrush" Color="#FFC26565" />
+
+        <Style TargetType="{x:Type Window}">
+            <Setter Property="Background" Value="{StaticResource AppWindowBackgroundBrush}" />
+            <Setter Property="Foreground" Value="{StaticResource AppTextBrush}" />
+            <Setter Property="FontFamily" Value="Segoe UI" />
+        </Style>
+
+        <Style TargetType="{x:Type TextBlock}">
+            <Setter Property="Foreground" Value="{StaticResource AppTextBrush}" />
+        </Style>
+
+        <Style TargetType="{x:Type GroupBox}">
+            <Setter Property="Background" Value="{StaticResource AppPanelBrush}" />
+            <Setter Property="BorderBrush" Value="{StaticResource AppBorderBrush}" />
+            <Setter Property="Foreground" Value="{StaticResource AppAccentBrush}" />
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="{x:Type GroupBox}">
+                        <Grid SnapsToDevicePixels="True">
+                            <Grid.RowDefinitions>
+                                <RowDefinition Height="Auto" />
+                                <RowDefinition Height="*" />
+                            </Grid.RowDefinitions>
+                            <Border Grid.Row="1"
+                                    Margin="0,3,0,0"
+                                    Background="{TemplateBinding Background}"
+                                    BorderBrush="{TemplateBinding BorderBrush}"
+                                    BorderThickness="1"
+                                    CornerRadius="4">
+                                <ContentPresenter ContentSource="Content" />
+                            </Border>
+                            <Border Grid.Row="0"
+                                    Margin="12,0,12,0"
+                                    Padding="8,0"
+                                    HorizontalAlignment="Left"
+                                    Background="{StaticResource AppWindowBackgroundBrush}">
+                                <ContentPresenter ContentSource="Header"
+                                                  RecognizesAccessKey="True" />
+                            </Border>
+                        </Grid>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
+
+        <Style TargetType="{x:Type Button}">
+            <Setter Property="Background" Value="{StaticResource AppButtonBrush}" />
+            <Setter Property="BorderBrush" Value="{StaticResource AppBorderBrush}" />
+            <Setter Property="Foreground" Value="{StaticResource AppTextBrush}" />
+            <Setter Property="Padding" Value="10,5" />
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="{x:Type Button}">
+                        <Border x:Name="Root"
+                                Background="{TemplateBinding Background}"
+                                BorderBrush="{TemplateBinding BorderBrush}"
+                                BorderThickness="1"
+                                CornerRadius="4">
+                            <ContentPresenter Margin="{TemplateBinding Padding}"
+                                              HorizontalAlignment="Center"
+                                              VerticalAlignment="Center"
+                                              RecognizesAccessKey="True" />
+                        </Border>
+                        <ControlTemplate.Triggers>
+                            <Trigger Property="IsMouseOver" Value="True">
+                                <Setter TargetName="Root" Property="Background" Value="{StaticResource AppButtonHoverBrush}" />
+                            </Trigger>
+                            <Trigger Property="IsPressed" Value="True">
+                                <Setter TargetName="Root" Property="Background" Value="{StaticResource AppButtonPressedBrush}" />
+                            </Trigger>
+                            <Trigger Property="IsEnabled" Value="False">
+                                <Setter TargetName="Root" Property="Opacity" Value="0.55" />
+                            </Trigger>
+                        </ControlTemplate.Triggers>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
+
+        <Style x:Key="PrimaryActionButtonStyle" TargetType="{x:Type Button}" BasedOn="{StaticResource {x:Type Button}}">
+            <Setter Property="Background" Value="{StaticResource AppPrimaryButtonBrush}" />
+            <Setter Property="BorderBrush" Value="#FF466B8C" />
+            <Setter Property="Foreground" Value="#FFF8FBFE" />
+            <Setter Property="FontWeight" Value="SemiBold" />
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="{x:Type Button}">
+                        <Border x:Name="Root"
+                                Background="{TemplateBinding Background}"
+                                BorderBrush="{TemplateBinding BorderBrush}"
+                                BorderThickness="1"
+                                CornerRadius="4">
+                            <ContentPresenter Margin="{TemplateBinding Padding}"
+                                              HorizontalAlignment="Center"
+                                              VerticalAlignment="Center"
+                                              RecognizesAccessKey="True" />
+                        </Border>
+                        <ControlTemplate.Triggers>
+                            <Trigger Property="IsMouseOver" Value="True">
+                                <Setter TargetName="Root" Property="Background" Value="{StaticResource AppPrimaryButtonHoverBrush}" />
+                            </Trigger>
+                            <Trigger Property="IsPressed" Value="True">
+                                <Setter TargetName="Root" Property="Background" Value="{StaticResource AppPrimaryButtonPressedBrush}" />
+                            </Trigger>
+                            <Trigger Property="IsEnabled" Value="False">
+                                <Setter TargetName="Root" Property="Opacity" Value="0.5" />
+                            </Trigger>
+                        </ControlTemplate.Triggers>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
+
+        <Style TargetType="{x:Type TextBox}">
+            <Setter Property="Background" Value="{StaticResource AppSurfaceBrush}" />
+            <Setter Property="BorderBrush" Value="{StaticResource AppBorderBrush}" />
+            <Setter Property="Foreground" Value="{StaticResource AppTextBrush}" />
+            <Setter Property="Padding" Value="6,4" />
+        </Style>
+
+        <Style TargetType="{x:Type ComboBox}">
+            <Setter Property="Background" Value="{StaticResource AppSurfaceBrush}" />
+            <Setter Property="BorderBrush" Value="{StaticResource AppBorderBrush}" />
+            <Setter Property="Foreground" Value="{StaticResource AppTextBrush}" />
+        </Style>
+
+        <Style TargetType="{x:Type DataGrid}">
+            <Setter Property="Background" Value="{StaticResource AppSurfaceBrush}" />
+            <Setter Property="BorderBrush" Value="{StaticResource AppBorderBrush}" />
+            <Setter Property="Foreground" Value="{StaticResource AppTextBrush}" />
+            <Setter Property="GridLinesVisibility" Value="Horizontal" />
+            <Setter Property="HeadersVisibility" Value="Column" />
+            <Setter Property="CanUserAddRows" Value="False" />
+            <Setter Property="CanUserDeleteRows" Value="False" />
+            <Setter Property="AlternatingRowBackground" Value="#FFF6FAFD" />
+            <Setter Property="SelectionUnit" Value="FullRow" />
+            <Setter Property="SelectionMode" Value="Single" />
+            <Setter Property="RowHeaderWidth" Value="0" />
+        </Style>
+
+        <Style TargetType="{x:Type StatusBar}">
+            <Setter Property="Background" Value="{StaticResource AppPanelBrush}" />
+            <Setter Property="BorderBrush" Value="{StaticResource AppBorderBrush}" />
+            <Setter Property="Foreground" Value="{StaticResource AppMutedTextBrush}" />
+        </Style>
+    </Application.Resources>
+</Application>
diff --git a/App.xaml.cs b/App.xaml.cs
new file mode 100644
index 0000000..d7cc151
--- /dev/null
+++ b/App.xaml.cs
@@ -0,0 +1,153 @@
+using System;
+using System.Globalization;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Markup;
+using System.Windows.Threading;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace CRAWLER;
+
+public partial class App : Application
+{
+    private IHost _host;
+
+    public App()
+    {
+        ApplyRussianCulture();
+        RegisterGlobalExceptionHandlers();
+    }
+
+    protected override async void OnStartup(StartupEventArgs e)
+    {
+        base.OnStartup(e);
+
+        try
+        {
+            _host = AppHost.Create();
+            await _host.StartAsync().ConfigureAwait(true);
+
+            MainWindow = _host.Services.GetRequiredService<MainWindow>();
+            MainWindow.Show();
+        }
+        catch (Exception ex)
+        {
+            MessageBox.Show(ex.Message, "CRAWLER", MessageBoxButton.OK, MessageBoxImage.Error);
+            Shutdown(-1);
+        }
+    }
+
+    protected override async void OnExit(ExitEventArgs e)
+    {
+        try
+        {
+            if (_host != null)
+            {
+                try
+                {
+                    await _host.StopAsync(TimeSpan.FromSeconds(5)).ConfigureAwait(true);
+                }
+                finally
+                {
+                    _host.Dispose();
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            ShowUnhandledException(ex, true);
+        }
+        finally
+        {
+            UnregisterGlobalExceptionHandlers();
+            base.OnExit(e);
+        }
+    }
+
+    private static void ApplyRussianCulture()
+    {
+        var culture = new CultureInfo("ru-RU");
+
+        CultureInfo.DefaultThreadCurrentCulture = culture;
+        CultureInfo.DefaultThreadCurrentUICulture = culture;
+        Thread.CurrentThread.CurrentCulture = culture;
+        Thread.CurrentThread.CurrentUICulture = culture;
+
+        FrameworkElement.LanguageProperty.OverrideMetadata(
+            typeof(FrameworkElement),
+            new FrameworkPropertyMetadata(XmlLanguage.GetLanguage(culture.IetfLanguageTag)));
+    }
+
+    private void RegisterGlobalExceptionHandlers()
+    {
+        DispatcherUnhandledException += OnDispatcherUnhandledException;
+        AppDomain.CurrentDomain.UnhandledException += OnCurrentDomainUnhandledException;
+        TaskScheduler.UnobservedTaskException += OnUnobservedTaskException;
+    }
+
+    private void UnregisterGlobalExceptionHandlers()
+    {
+        DispatcherUnhandledException -= OnDispatcherUnhandledException;
+        AppDomain.CurrentDomain.UnhandledException -= OnCurrentDomainUnhandledException;
+        TaskScheduler.UnobservedTaskException -= OnUnobservedTaskException;
+    }
+
+    private void OnDispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
+    {
+        ShowUnhandledException(e.Exception, false);
+        e.Handled = true;
+    }
+
+    private void OnCurrentDomainUnhandledException(object sender, UnhandledExceptionEventArgs e)
+    {
+        if (e.ExceptionObject is Exception exception)
+        {
+            ShowUnhandledException(exception, e.IsTerminating);
+            return;
+        }
+
+        MessageBox.Show(
+            e.ExceptionObject == null ? "Произошла необработанная ошибка." : e.ExceptionObject.ToString(),
+            e.IsTerminating ? "CRAWLER - критическая ошибка" : "CRAWLER",
+            MessageBoxButton.OK,
+            MessageBoxImage.Error);
+    }
+
+    private void OnUnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs e)
+    {
+        ShowUnhandledException(e.Exception, false);
+        e.SetObserved();
+    }
+
+    private static void ShowUnhandledException(Exception exception, bool isCritical)
+    {
+        var actualException = UnwrapException(exception);
+        var message = string.IsNullOrWhiteSpace(actualException.Message)
+            ? actualException.ToString()
+            : actualException.Message;
+
+        MessageBox.Show(
+            message,
+            isCritical ? "CRAWLER - критическая ошибка" : "CRAWLER",
+            MessageBoxButton.OK,
+            MessageBoxImage.Error);
+    }
+
+    private static Exception UnwrapException(Exception exception)
+    {
+        if (exception is AggregateException aggregateException)
+        {
+            var flattened = aggregateException.Flatten();
+            if (flattened.InnerExceptions.Count == 1)
+            {
+                return UnwrapException(flattened.InnerExceptions[0]);
+            }
+
+            return flattened;
+        }
+
+        return exception;
+    }
+}
diff --git a/AppHost.cs b/AppHost.cs
new file mode 100644
index 0000000..8b23428
--- /dev/null
+++ b/AppHost.cs
@@ -0,0 +1,47 @@
+using System;
+using CRAWLER.Parsing;
+using CRAWLER.Services;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace CRAWLER;
+
+internal static class AppHost
+{
+    public static IHost Create()
+    {
+        return Host.CreateDefaultBuilder()
+            .UseContentRoot(AppContext.BaseDirectory)
+            .ConfigureAppConfiguration((_, config) =>
+            {
+                config.Sources.Clear();
+                config.SetBasePath(AppContext.BaseDirectory);
+                config.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
+                config.AddEnvironmentVariables();
+            })
+            .ConfigureServices((context, services) =>
+            {
+                services.AddSingleton<IDatabaseConnectionFactory, SqlServerConnectionFactory>();
+                services.AddSingleton<DatabaseInitializer>();
+                services.AddSingleton<InstrumentRepository>();
+                services.AddSingleton<CatalogPageParser>();
+                services.AddSingleton<DetailPageParser>();
+                services.AddSingleton<KtoPoveritClient>();
+                services.AddSingleton<PdfStorageService>();
+                services.AddSingleton<InstrumentCatalogService>();
+                services.AddSingleton<IPdfOpener, PdfShellService>();
+                services.AddSingleton<IFilePickerService, FilePickerService>();
+                services.AddTransient<MainWindow>(provider => new MainWindow(
+                    provider.GetRequiredService<InstrumentCatalogService>(),
+                    provider.GetRequiredService<IPdfOpener>(),
+                    provider.GetRequiredService<IFilePickerService>()));
+            })
+            .UseDefaultServiceProvider((_, options) =>
+            {
+                options.ValidateOnBuild = true;
+                options.ValidateScopes = true;
+            })
+            .Build();
+    }
+}
diff --git a/AssemblyInfo.cs b/AssemblyInfo.cs
new file mode 100644
index 0000000..cc29e7f
--- /dev/null
+++ b/AssemblyInfo.cs
@@ -0,0 +1,10 @@
+using System.Windows;
+
+[assembly:ThemeInfo(
+    ResourceDictionaryLocation.None,            //where theme specific resource dictionaries are located
+                                                //(used if a resource is not found in the page,
+                                                // or application resource dictionaries)
+    ResourceDictionaryLocation.SourceAssembly   //where the generic resource dictionary is located
+                                                //(used if a resource is not found in the page,
+                                                // app, or any theme specific resource dictionaries)
+)]
diff --git a/CRAWLER.csproj b/CRAWLER.csproj
new file mode 100644
index 0000000..9aacd80
--- /dev/null
+++ b/CRAWLER.csproj
@@ -0,0 +1,37 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net10.0-windows</TargetFramework>
+    <Nullable>disable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <UseWPF>true</UseWPF>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Remove="obj-temp-*\**\*.cs;bin-temp-*\**\*.cs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="HtmlAgilityPack" Version="1.12.4" />
+    <PackageReference Include="Microsoft.Data.SqlClient" Version="6.1.1" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="10.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Include="appsettings.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="SampleData\catalog-page-sample.html">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="SampleData\detail-page-sample.html">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+
+</Project>
diff --git a/CRAWLER.sln b/CRAWLER.sln
new file mode 100644
index 0000000..c2e5296
--- /dev/null
+++ b/CRAWLER.sln
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 18
+VisualStudioVersion = 18.4.11626.88 stable
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CRAWLER", "CRAWLER.csproj", "{99A6FD50-529F-431C-8F74-7F37BBA2948E}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{99A6FD50-529F-431C-8F74-7F37BBA2948E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{99A6FD50-529F-431C-8F74-7F37BBA2948E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{99A6FD50-529F-431C-8F74-7F37BBA2948E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{99A6FD50-529F-431C-8F74-7F37BBA2948E}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {607CB39E-759D-4950-B3DE-F3008151509A}
+	EndGlobalSection
+EndGlobal
diff --git a/Configuration/CrawlerOptions.cs b/Configuration/CrawlerOptions.cs
new file mode 100644
index 0000000..39f17e0
--- /dev/null
+++ b/Configuration/CrawlerOptions.cs
@@ -0,0 +1,12 @@
+namespace CRAWLER.Configuration;
+
+internal sealed class CrawlerOptions
+{
+    public string BaseUrl { get; set; } = "https://www.ktopoverit.ru";
+    public string CatalogPathFormat { get; set; } = "/poverka/gosreestr_sredstv_izmereniy?page={0}";
+    public int RequestDelayMilliseconds { get; set; } = 350;
+    public int DefaultPagesToScan { get; set; } = 1;
+    public string PdfStoragePath { get; set; } = "%LOCALAPPDATA%\\CRAWLER\\PdfStore";
+    public int TimeoutSeconds { get; set; } = 30;
+    public string UserAgent { get; set; } = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) CRAWLER/1.0";
+}
diff --git a/Configuration/DatabaseOptions.cs b/Configuration/DatabaseOptions.cs
new file mode 100644
index 0000000..ab69dd9
--- /dev/null
+++ b/Configuration/DatabaseOptions.cs
@@ -0,0 +1,19 @@
+namespace CRAWLER.Configuration;
+
+internal sealed class DatabaseOptions
+{
+    public string ApplicationName { get; set; } = "CRAWLER";
+    public int CommandTimeoutSeconds { get; set; } = 60;
+    public int ConnectRetryCount { get; set; } = 3;
+    public int ConnectRetryIntervalSeconds { get; set; } = 5;
+    public int ConnectTimeoutSeconds { get; set; } = 15;
+    public string Database { get; set; } = "CRAWLER";
+    public bool Encrypt { get; set; }
+    public bool IntegratedSecurity { get; set; } = true;
+    public bool MultipleActiveResultSets { get; set; } = true;
+    public bool Pooling { get; set; } = true;
+    public int MaxPoolSize { get; set; } = 100;
+    public int MinPoolSize { get; set; }
+    public string Server { get; set; } = @".\SQLEXPRESS";
+    public bool TrustServerCertificate { get; set; } = true;
+}
diff --git a/Dialogs/EditInstrumentWindow.xaml b/Dialogs/EditInstrumentWindow.xaml
new file mode 100644
index 0000000..3b489ec
--- /dev/null
+++ b/Dialogs/EditInstrumentWindow.xaml
@@ -0,0 +1,175 @@
+<Window x:Class="CRAWLER.Dialogs.EditInstrumentWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        Title="{Binding WindowTitle}"
+        Height="820"
+        Width="980"
+        MinHeight="680"
+        MinWidth="860"
+        WindowStartupLocation="CenterOwner"
+        ResizeMode="CanResize">
+    <Grid Margin="12">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="*" />
+            <RowDefinition Height="Auto" />
+        </Grid.RowDefinitions>
+
+        <TabControl Grid.Row="0">
+            <TabItem Header="Основное">
+                <ScrollViewer VerticalScrollBarVisibility="Auto">
+                    <Grid Margin="8">
+                        <Grid.ColumnDefinitions>
+                            <ColumnDefinition Width="210" />
+                            <ColumnDefinition Width="*" />
+                        </Grid.ColumnDefinitions>
+                        <Grid.RowDefinitions>
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="Auto" />
+                        </Grid.RowDefinitions>
+
+                        <TextBlock Grid.Row="0" Grid.Column="0" Margin="0,0,8,8" VerticalAlignment="Center" Text="Номер в госреестре" />
+                        <TextBox Grid.Row="0" Grid.Column="1" Margin="0,0,0,8" Text="{Binding Draft.RegistryNumber, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Grid.Row="1" Grid.Column="0" Margin="0,0,8,8" VerticalAlignment="Center" Text="Наименование" />
+                        <TextBox Grid.Row="1" Grid.Column="1" Margin="0,0,0,8" Text="{Binding Draft.Name, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Grid.Row="2" Grid.Column="0" Margin="0,0,8,8" VerticalAlignment="Center" Text="Тип" />
+                        <TextBox Grid.Row="2" Grid.Column="1" Margin="0,0,0,8" Text="{Binding Draft.TypeDesignation, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Grid.Row="3" Grid.Column="0" Margin="0,0,8,8" VerticalAlignment="Center" Text="Производитель" />
+                        <TextBox Grid.Row="3" Grid.Column="1" Margin="0,0,0,8" Text="{Binding Draft.Manufacturer, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" />
+
+                        <TextBlock Grid.Row="4" Grid.Column="0" Margin="0,0,8,8" VerticalAlignment="Center" Text="МПИ" />
+                        <TextBox Grid.Row="4" Grid.Column="1" Margin="0,0,0,8" Text="{Binding Draft.VerificationInterval, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Grid.Row="5" Grid.Column="0" Margin="0,0,8,8" VerticalAlignment="Center" Text="Срок/зав. номер" />
+                        <TextBox Grid.Row="5" Grid.Column="1" Margin="0,0,0,8" Text="{Binding Draft.CertificateOrSerialNumber, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Grid.Row="6" Grid.Column="0" Margin="0,0,8,8" VerticalAlignment="Center" Text="Ссылка на источник" />
+                        <TextBox Grid.Row="6" Grid.Column="1" Margin="0,0,0,8" Text="{Binding Draft.DetailUrl, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Grid.Row="7" Grid.Column="0" Margin="0,0,8,0" VerticalAlignment="Center" Text="Источник записи" />
+                        <TextBox Grid.Row="7" Grid.Column="1" Text="{Binding Draft.SourceSystem, UpdateSourceTrigger=PropertyChanged}" />
+                    </Grid>
+                </ScrollViewer>
+            </TabItem>
+
+            <TabItem Header="Текстовые поля">
+                <ScrollViewer VerticalScrollBarVisibility="Auto">
+                    <StackPanel Margin="8">
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Поверка партии" />
+                        <TextBox Margin="0,0,0,10" Text="{Binding Draft.AllowsBatchVerification, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Периодическая поверка" />
+                        <TextBox Margin="0,0,0,10" Text="{Binding Draft.HasPeriodicVerification, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Сведения о типе" />
+                        <TextBox Margin="0,0,0,10" Text="{Binding Draft.TypeInfo, UpdateSourceTrigger=PropertyChanged}" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Назначение" />
+                        <TextBox Margin="0,0,0,10" MinHeight="60" Text="{Binding Draft.Purpose, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Описание" />
+                        <TextBox Margin="0,0,0,10" MinHeight="70" Text="{Binding Draft.Description, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Программное обеспечение" />
+                        <TextBox Margin="0,0,0,10" MinHeight="60" Text="{Binding Draft.Software, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Метрологические и технические характеристики" />
+                        <TextBox Margin="0,0,0,10" MinHeight="70" Text="{Binding Draft.MetrologicalCharacteristics, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Комплектность" />
+                        <TextBox Margin="0,0,0,10" MinHeight="60" Text="{Binding Draft.Completeness, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Поверка" />
+                        <TextBox Margin="0,0,0,10" MinHeight="60" Text="{Binding Draft.Verification, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Нормативные и технические документы" />
+                        <TextBox Margin="0,0,0,10" MinHeight="60" Text="{Binding Draft.RegulatoryDocuments, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Заявитель" />
+                        <TextBox Margin="0,0,0,10" MinHeight="60" Text="{Binding Draft.Applicant, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                        <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Испытательный центр" />
+                        <TextBox MinHeight="60" Text="{Binding Draft.TestCenter, UpdateSourceTrigger=PropertyChanged}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+                    </StackPanel>
+                </ScrollViewer>
+            </TabItem>
+
+            <TabItem Header="PDF">
+                <Grid Margin="8">
+                    <Grid.RowDefinitions>
+                        <RowDefinition Height="Auto" />
+                        <RowDefinition Height="Auto" />
+                        <RowDefinition Height="*" />
+                    </Grid.RowDefinitions>
+
+                    <TextBlock Grid.Row="0"
+                               Margin="0,0,0,8"
+                               Text="PDF, уже сохранённые у записи, показаны ниже. Новые файлы будут скопированы при сохранении." />
+
+                    <GroupBox Grid.Row="1" Header="Уже привязанные PDF">
+                        <Grid Margin="8">
+                            <DataGrid ItemsSource="{Binding ExistingAttachments}"
+                                      IsReadOnly="True"
+                                      Height="180">
+                                <DataGrid.Columns>
+                                    <DataGridTextColumn Width="160" Binding="{Binding Kind}" Header="Тип" />
+                                    <DataGridTextColumn Width="200" Binding="{Binding Title}" Header="Заголовок" />
+                                    <DataGridTextColumn Width="*" Binding="{Binding LocalPath}" Header="Локальный путь" />
+                                </DataGrid.Columns>
+                            </DataGrid>
+                        </Grid>
+                    </GroupBox>
+
+                    <GroupBox Grid.Row="2" Margin="0,12,0,0" Header="Очередь новых PDF">
+                        <Grid Margin="8">
+                            <Grid.RowDefinitions>
+                                <RowDefinition Height="Auto" />
+                                <RowDefinition Height="*" />
+                            </Grid.RowDefinitions>
+
+                            <StackPanel Grid.Row="0"
+                                        Margin="0,0,0,8"
+                                        Orientation="Horizontal">
+                                <Button Margin="0,0,8,0"
+                                        Click="BrowsePdfButton_Click"
+                                        Content="Добавить PDF..." />
+                                <Button Click="RemovePendingPdfButton_Click"
+                                        Content="Убрать из очереди" />
+                            </StackPanel>
+
+                            <DataGrid Grid.Row="1"
+                                      ItemsSource="{Binding PendingPdfFiles}"
+                                      SelectedItem="{Binding SelectedPendingPdf, Mode=TwoWay}"
+                                      IsReadOnly="True">
+                                <DataGrid.Columns>
+                                    <DataGridTextColumn Width="220" Binding="{Binding DisplayName}" Header="Файл" />
+                                    <DataGridTextColumn Width="*" Binding="{Binding SourcePath}" Header="Исходный путь" />
+                                </DataGrid.Columns>
+                            </DataGrid>
+                        </Grid>
+                    </GroupBox>
+                </Grid>
+            </TabItem>
+        </TabControl>
+
+        <StackPanel Grid.Row="1"
+                    Margin="0,12,0,0"
+                    HorizontalAlignment="Right"
+                    Orientation="Horizontal">
+            <Button Margin="0,0,8,0"
+                    Click="SaveButton_Click"
+                    Style="{StaticResource PrimaryActionButtonStyle}"
+                    Content="Сохранить" />
+            <Button Click="CancelButton_Click"
+                    Content="Отмена" />
+        </StackPanel>
+    </Grid>
+</Window>
diff --git a/Dialogs/EditInstrumentWindow.xaml.cs b/Dialogs/EditInstrumentWindow.xaml.cs
new file mode 100644
index 0000000..71528f6
--- /dev/null
+++ b/Dialogs/EditInstrumentWindow.xaml.cs
@@ -0,0 +1,46 @@
+using System.Windows;
+using CRAWLER.Services;
+using CRAWLER.ViewModels;
+
+namespace CRAWLER.Dialogs;
+
+public partial class EditInstrumentWindow : Window
+{
+    private readonly IFilePickerService _filePickerService;
+
+    internal EditInstrumentWindow(EditInstrumentWindowViewModel viewModel, IFilePickerService filePickerService)
+    {
+        InitializeComponent();
+        ViewModel = viewModel;
+        _filePickerService = filePickerService;
+        DataContext = ViewModel;
+    }
+
+    internal EditInstrumentWindowViewModel ViewModel { get; }
+
+    private void BrowsePdfButton_Click(object sender, RoutedEventArgs e)
+    {
+        ViewModel.AddPendingFiles(_filePickerService.PickPdfFiles(true));
+    }
+
+    private void RemovePendingPdfButton_Click(object sender, RoutedEventArgs e)
+    {
+        ViewModel.RemovePendingSelected();
+    }
+
+    private void SaveButton_Click(object sender, RoutedEventArgs e)
+    {
+        if (!ViewModel.Validate(out var errorMessage))
+        {
+            MessageBox.Show(errorMessage, "CRAWLER", MessageBoxButton.OK, MessageBoxImage.Warning);
+            return;
+        }
+
+        DialogResult = true;
+    }
+
+    private void CancelButton_Click(object sender, RoutedEventArgs e)
+    {
+        DialogResult = false;
+    }
+}
diff --git a/Infrastructure/MvvmInfrastructure.cs b/Infrastructure/MvvmInfrastructure.cs
new file mode 100644
index 0000000..caeb6e6
--- /dev/null
+++ b/Infrastructure/MvvmInfrastructure.cs
@@ -0,0 +1,126 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using System.Threading.Tasks;
+using System.Windows.Input;
+
+namespace CRAWLER.Infrastructure;
+
+public abstract class ObservableObject : INotifyPropertyChanged
+{
+    public event PropertyChangedEventHandler PropertyChanged;
+
+    protected bool SetProperty<T>(ref T field, T value, [CallerMemberName] string propertyName = null)
+    {
+        if (EqualityComparer<T>.Default.Equals(field, value))
+        {
+            return false;
+        }
+
+        field = value;
+        OnPropertyChanged(propertyName);
+        return true;
+    }
+
+    protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
+    {
+        var handler = PropertyChanged;
+        if (handler != null)
+        {
+            handler(this, new PropertyChangedEventArgs(propertyName));
+        }
+    }
+}
+
+internal sealed class RelayCommand : ICommand
+{
+    private readonly Action<object> _execute;
+    private readonly Predicate<object> _canExecute;
+
+    public RelayCommand(Action<object> execute, Predicate<object> canExecute = null)
+    {
+        _execute = execute ?? throw new ArgumentNullException(nameof(execute));
+        _canExecute = canExecute;
+    }
+
+    public event EventHandler CanExecuteChanged;
+
+    public bool CanExecute(object parameter)
+    {
+        return _canExecute == null || _canExecute(parameter);
+    }
+
+    public void Execute(object parameter)
+    {
+        _execute(parameter);
+    }
+
+    public void RaiseCanExecuteChanged()
+    {
+        var handler = CanExecuteChanged;
+        if (handler != null)
+        {
+            handler(this, EventArgs.Empty);
+        }
+    }
+}
+
+internal sealed class AsyncRelayCommand : ICommand
+{
+    private readonly Func<object, Task> _executeAsync;
+    private readonly Predicate<object> _canExecute;
+    private bool _isExecuting;
+
+    public AsyncRelayCommand(Func<Task> executeAsync, Func<bool> canExecute = null)
+        : this(_ => executeAsync(), canExecute == null ? null : new Predicate<object>(_ => canExecute()))
+    {
+    }
+
+    public AsyncRelayCommand(Func<object, Task> executeAsync, Predicate<object> canExecute = null)
+    {
+        _executeAsync = executeAsync ?? throw new ArgumentNullException(nameof(executeAsync));
+        _canExecute = canExecute;
+    }
+
+    public event EventHandler CanExecuteChanged;
+
+    public bool CanExecute(object parameter)
+    {
+        return !_isExecuting && (_canExecute == null || _canExecute(parameter));
+    }
+
+    public async void Execute(object parameter)
+    {
+        await ExecuteAsync(parameter);
+    }
+
+    public async Task ExecuteAsync(object parameter = null)
+    {
+        if (!CanExecute(parameter))
+        {
+            return;
+        }
+
+        try
+        {
+            _isExecuting = true;
+            RaiseCanExecuteChanged();
+            await _executeAsync(parameter);
+        }
+        finally
+        {
+            _isExecuting = false;
+            RaiseCanExecuteChanged();
+        }
+    }
+
+    public void RaiseCanExecuteChanged()
+    {
+        var handler = CanExecuteChanged;
+        if (handler != null)
+        {
+            handler(this, EventArgs.Empty);
+        }
+    }
+}
diff --git a/MainWindow.xaml b/MainWindow.xaml
new file mode 100644
index 0000000..2dab736
--- /dev/null
+++ b/MainWindow.xaml
@@ -0,0 +1,268 @@
+<Window x:Class="CRAWLER.MainWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        mc:Ignorable="d"
+        Title="CRAWLER"
+        Height="920"
+        Width="1560"
+        MinHeight="760"
+        MinWidth="1240"
+        WindowState="Maximized"
+        Loaded="Window_Loaded">
+    <Window.Resources>
+        <Style x:Key="GhostGridSplitterStyle" TargetType="GridSplitter">
+            <Setter Property="Background" Value="Transparent" />
+            <Setter Property="BorderBrush" Value="Transparent" />
+            <Setter Property="BorderThickness" Value="0" />
+            <Setter Property="ShowsPreview" Value="True" />
+            <Style.Triggers>
+                <Trigger Property="IsMouseOver" Value="True">
+                    <Setter Property="Background" Value="#D7DADF" />
+                    <Setter Property="BorderBrush" Value="#BCC1C7" />
+                    <Setter Property="BorderThickness" Value="1" />
+                </Trigger>
+            </Style.Triggers>
+        </Style>
+    </Window.Resources>
+    <Grid Margin="12">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto" />
+            <RowDefinition Height="*" />
+            <RowDefinition Height="Auto" />
+        </Grid.RowDefinitions>
+
+        <Border Grid.Row="0"
+                Margin="0,0,0,12"
+                Padding="12"
+                Background="{StaticResource AppPanelBrush}"
+                BorderBrush="{StaticResource AppBorderBrush}"
+                BorderThickness="1"
+                CornerRadius="4">
+            <DockPanel LastChildFill="False">
+                <StackPanel DockPanel.Dock="Left"
+                            Orientation="Horizontal"
+                            VerticalAlignment="Center">
+                    <TextBlock Margin="0,0,8,0"
+                               VerticalAlignment="Center"
+                               FontWeight="SemiBold"
+                               Text="Поиск" />
+                    <TextBox Width="320"
+                             Margin="0,0,10,0"
+                             VerticalAlignment="Center"
+                             KeyDown="SearchTextBox_KeyDown"
+                             Text="{Binding SearchText, UpdateSourceTrigger=PropertyChanged}" />
+                    <Button Margin="0,0,8,0"
+                            Click="RefreshButton_Click"
+                            Content="Обновить список" />
+                    <TextBlock Margin="12,0,8,0"
+                               VerticalAlignment="Center"
+                               FontWeight="SemiBold"
+                               Text="Страниц для сайта" />
+                    <TextBox Width="64"
+                             Margin="0,0,10,0"
+                             VerticalAlignment="Center"
+                             Text="{Binding PagesToScan, UpdateSourceTrigger=PropertyChanged}" />
+                    <Button Margin="0,0,8,0"
+                            Style="{StaticResource PrimaryActionButtonStyle}"
+                            Click="SyncButton_Click"
+                            Content="Обновить с сайта" />
+                </StackPanel>
+
+                <StackPanel DockPanel.Dock="Right"
+                            Orientation="Horizontal"
+                            HorizontalAlignment="Right">
+                    <Button Margin="0,0,8,0"
+                            Click="AddButton_Click"
+                            Content="Добавить" />
+                    <Button Margin="0,0,8,0"
+                            Click="EditButton_Click"
+                            Content="Изменить" />
+                    <Button Click="DeleteButton_Click"
+                            Content="Удалить" />
+                </StackPanel>
+            </DockPanel>
+        </Border>
+
+        <Grid Grid.Row="1">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="2.2*" />
+                <ColumnDefinition Width="10" />
+                <ColumnDefinition Width="1.6*" />
+            </Grid.ColumnDefinitions>
+
+            <GroupBox Grid.Column="0" Header="Реестр средств измерений">
+                <Grid Margin="8">
+                    <DataGrid x:Name="InstrumentGrid"
+                              ItemsSource="{Binding Instruments}"
+                              SelectedItem="{Binding SelectedSummary, Mode=TwoWay}"
+                              IsReadOnly="True"
+                              MouseDoubleClick="InstrumentGrid_MouseDoubleClick">
+                        <DataGrid.Columns>
+                            <DataGridTextColumn Width="120" Binding="{Binding RegistryNumber}" Header="Госреестр" />
+                            <DataGridTextColumn Width="2*" Binding="{Binding Name}" Header="Наименование" />
+                            <DataGridTextColumn Width="160" Binding="{Binding TypeDesignation}" Header="Тип" />
+                            <DataGridTextColumn Width="2*" Binding="{Binding Manufacturer}" Header="Производитель" />
+                            <DataGridTextColumn Width="120" Binding="{Binding VerificationInterval}" Header="МПИ" />
+                            <DataGridTextColumn Width="110" Binding="{Binding SourceSystem}" Header="Источник" />
+                            <DataGridTextColumn Width="140" Binding="{Binding UpdatedAt, StringFormat=dd.MM.yyyy HH:mm}" Header="Обновлено" />
+                        </DataGrid.Columns>
+                    </DataGrid>
+                </Grid>
+            </GroupBox>
+
+            <GridSplitter Grid.Column="1"
+                          HorizontalAlignment="Stretch"
+                          VerticalAlignment="Stretch"
+                          ResizeDirection="Columns"
+                          ResizeBehavior="PreviousAndNext"
+                          Style="{StaticResource GhostGridSplitterStyle}"
+                          Cursor="SizeWE" />
+
+            <GroupBox Grid.Column="2" Header="Карточка записи">
+                <Grid Margin="8">
+                    <Grid.RowDefinitions>
+                        <RowDefinition Height="Auto" />
+                        <RowDefinition Height="*" />
+                    </Grid.RowDefinitions>
+
+                    <DockPanel Grid.Row="0" Margin="0,0,0,8" LastChildFill="False">
+                        <TextBlock DockPanel.Dock="Left"
+                                   FontSize="16"
+                                   FontWeight="SemiBold"
+                                   Text="{Binding SelectedInstrument.Name}" />
+                        <Button DockPanel.Dock="Right"
+                                Padding="8,4"
+                                Click="OpenSourceButton_Click"
+                                Content="Открыть источник" />
+                    </DockPanel>
+
+                    <TabControl Grid.Row="1">
+                        <TabItem Header="Общее">
+                            <ScrollViewer VerticalScrollBarVisibility="Auto">
+                                <Grid Margin="8">
+                                    <Grid.ColumnDefinitions>
+                                        <ColumnDefinition Width="180" />
+                                        <ColumnDefinition Width="*" />
+                                    </Grid.ColumnDefinitions>
+                                    <Grid.RowDefinitions>
+                                        <RowDefinition Height="Auto" />
+                                        <RowDefinition Height="Auto" />
+                                        <RowDefinition Height="Auto" />
+                                        <RowDefinition Height="Auto" />
+                                        <RowDefinition Height="Auto" />
+                                        <RowDefinition Height="Auto" />
+                                        <RowDefinition Height="Auto" />
+                                        <RowDefinition Height="Auto" />
+                                        <RowDefinition Height="*" />
+                                    </Grid.RowDefinitions>
+
+                                    <TextBlock Grid.Row="0" Grid.Column="0" Margin="0,0,8,6" VerticalAlignment="Center" Text="Номер в госреестре" />
+                                    <TextBox Grid.Row="0" Grid.Column="1" Margin="0,0,0,6" IsReadOnly="True" Text="{Binding SelectedInstrument.RegistryNumber}" />
+
+                                    <TextBlock Grid.Row="1" Grid.Column="0" Margin="0,0,8,6" VerticalAlignment="Center" Text="Тип" />
+                                    <TextBox Grid.Row="1" Grid.Column="1" Margin="0,0,0,6" IsReadOnly="True" Text="{Binding SelectedInstrument.TypeDesignation}" />
+
+                                    <TextBlock Grid.Row="2" Grid.Column="0" Margin="0,0,8,6" VerticalAlignment="Center" Text="Производитель" />
+                                    <TextBox Grid.Row="2" Grid.Column="1" Margin="0,0,0,6" IsReadOnly="True" Text="{Binding SelectedInstrument.Manufacturer}" TextWrapping="Wrap" />
+
+                                    <TextBlock Grid.Row="3" Grid.Column="0" Margin="0,0,8,6" VerticalAlignment="Center" Text="МПИ" />
+                                    <TextBox Grid.Row="3" Grid.Column="1" Margin="0,0,0,6" IsReadOnly="True" Text="{Binding SelectedInstrument.VerificationInterval}" />
+
+                                    <TextBlock Grid.Row="4" Grid.Column="0" Margin="0,0,8,6" VerticalAlignment="Center" Text="Срок/зав. номер" />
+                                    <TextBox Grid.Row="4" Grid.Column="1" Margin="0,0,0,6" IsReadOnly="True" Text="{Binding SelectedInstrument.CertificateOrSerialNumber}" />
+
+                                    <TextBlock Grid.Row="5" Grid.Column="0" Margin="0,0,8,6" VerticalAlignment="Center" Text="Поверка партии" />
+                                    <TextBox Grid.Row="5" Grid.Column="1" Margin="0,0,0,6" IsReadOnly="True" Text="{Binding SelectedInstrument.AllowsBatchVerification}" />
+
+                                    <TextBlock Grid.Row="6" Grid.Column="0" Margin="0,0,8,6" VerticalAlignment="Center" Text="Периодическая поверка" />
+                                    <TextBox Grid.Row="6" Grid.Column="1" Margin="0,0,0,6" IsReadOnly="True" Text="{Binding SelectedInstrument.HasPeriodicVerification}" />
+
+                                    <TextBlock Grid.Row="7" Grid.Column="0" Margin="0,0,8,6" VerticalAlignment="Center" Text="Источник" />
+                                    <TextBox Grid.Row="7" Grid.Column="1" Margin="0,0,0,6" IsReadOnly="True" Text="{Binding SelectedInstrument.SourceSystem}" />
+
+                                    <TextBlock Grid.Row="8" Grid.Column="0" Margin="0,0,8,0" VerticalAlignment="Top" Text="Ссылка" />
+                                    <TextBox Grid.Row="8" Grid.Column="1" IsReadOnly="True" Text="{Binding SelectedInstrument.DetailUrl}" TextWrapping="Wrap" VerticalScrollBarVisibility="Auto" />
+                                </Grid>
+                            </ScrollViewer>
+                        </TabItem>
+
+                        <TabItem Header="Текстовые поля">
+                            <ScrollViewer VerticalScrollBarVisibility="Auto">
+                                <StackPanel Margin="8">
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Назначение" />
+                                    <TextBox Margin="0,0,0,10" IsReadOnly="True" MinHeight="60" Text="{Binding SelectedInstrument.Purpose}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Описание" />
+                                    <TextBox Margin="0,0,0,10" IsReadOnly="True" MinHeight="70" Text="{Binding SelectedInstrument.Description}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Программное обеспечение" />
+                                    <TextBox Margin="0,0,0,10" IsReadOnly="True" MinHeight="60" Text="{Binding SelectedInstrument.Software}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Метрологические и технические характеристики" />
+                                    <TextBox Margin="0,0,0,10" IsReadOnly="True" MinHeight="70" Text="{Binding SelectedInstrument.MetrologicalCharacteristics}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Комплектность" />
+                                    <TextBox Margin="0,0,0,10" IsReadOnly="True" MinHeight="60" Text="{Binding SelectedInstrument.Completeness}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Поверка" />
+                                    <TextBox Margin="0,0,0,10" IsReadOnly="True" MinHeight="60" Text="{Binding SelectedInstrument.Verification}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Нормативные и технические документы" />
+                                    <TextBox Margin="0,0,0,10" IsReadOnly="True" MinHeight="60" Text="{Binding SelectedInstrument.RegulatoryDocuments}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Заявитель" />
+                                    <TextBox Margin="0,0,0,10" IsReadOnly="True" MinHeight="60" Text="{Binding SelectedInstrument.Applicant}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+
+                                    <TextBlock Margin="0,0,0,4" FontWeight="SemiBold" Text="Испытательный центр" />
+                                    <TextBox IsReadOnly="True" MinHeight="60" Text="{Binding SelectedInstrument.TestCenter}" TextWrapping="Wrap" AcceptsReturn="True" VerticalScrollBarVisibility="Auto" />
+                                </StackPanel>
+                            </ScrollViewer>
+                        </TabItem>
+
+                        <TabItem Header="PDF">
+                            <Grid Margin="8">
+                                <Grid.RowDefinitions>
+                                    <RowDefinition Height="Auto" />
+                                    <RowDefinition Height="*" />
+                                </Grid.RowDefinitions>
+
+                                <StackPanel Grid.Row="0"
+                                            Margin="0,0,0,8"
+                                            Orientation="Horizontal">
+                                    <Button Margin="0,0,8,0"
+                                            Click="AddPdfButton_Click"
+                                            Content="Добавить PDF вручную" />
+                                    <Button Margin="0,0,8,0"
+                                            Click="OpenAttachmentButton_Click"
+                                            Content="Открыть выбранный PDF" />
+                                    <Button Click="RemoveAttachmentButton_Click"
+                                            Content="Удалить привязку" />
+                                </StackPanel>
+
+                                <DataGrid x:Name="AttachmentGrid"
+                                          Grid.Row="1"
+                                          ItemsSource="{Binding SelectedInstrument.Attachments}"
+                                          IsReadOnly="True">
+                                    <DataGrid.Columns>
+                                        <DataGridTextColumn Width="160" Binding="{Binding Kind}" Header="Тип файла" />
+                                        <DataGridTextColumn Width="180" Binding="{Binding Title}" Header="Заголовок" />
+                                        <DataGridTextColumn Width="*" Binding="{Binding LocalPath}" Header="Локальный путь" />
+                                        <DataGridCheckBoxColumn Width="100" Binding="{Binding IsManual}" Header="Ручной" />
+                                    </DataGrid.Columns>
+                                </DataGrid>
+                            </Grid>
+                        </TabItem>
+                    </TabControl>
+                </Grid>
+            </GroupBox>
+        </Grid>
+
+        <StatusBar Grid.Row="2" Margin="0,12,0,0">
+            <StatusBarItem>
+                <TextBlock Text="{Binding StatusText}" />
+            </StatusBarItem>
+        </StatusBar>
+    </Grid>
+</Window>
diff --git a/MainWindow.xaml.cs b/MainWindow.xaml.cs
new file mode 100644
index 0000000..b06073e
--- /dev/null
+++ b/MainWindow.xaml.cs
@@ -0,0 +1,188 @@
+using System;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Input;
+using CRAWLER.Models;
+using CRAWLER.Services;
+using CRAWLER.ViewModels;
+
+namespace CRAWLER;
+
+public partial class MainWindow : Window
+{
+    private readonly IFilePickerService _filePickerService;
+    private readonly MainWindowViewModel _viewModel;
+
+    internal MainWindow(
+        InstrumentCatalogService catalogService,
+        IPdfOpener pdfOpener,
+        IFilePickerService filePickerService)
+    {
+        InitializeComponent();
+        _filePickerService = filePickerService;
+        _viewModel = new MainWindowViewModel(catalogService, pdfOpener);
+        DataContext = _viewModel;
+    }
+
+    private async void Window_Loaded(object sender, RoutedEventArgs e)
+    {
+        await ExecuteUiAsync(_viewModel.InitializeAsync);
+    }
+
+    private async void RefreshButton_Click(object sender, RoutedEventArgs e)
+    {
+        await ExecuteUiAsync(() => _viewModel.RefreshAsync());
+    }
+
+    private async void SyncButton_Click(object sender, RoutedEventArgs e)
+    {
+        await ExecuteUiAsync(async () =>
+        {
+            var result = await _viewModel.SyncAsync();
+            MessageBox.Show(
+                $"Обработано страниц: {result.PagesScanned}\n" +
+                $"Обработано записей: {result.ProcessedItems}\n" +
+                $"Добавлено: {result.AddedRecords}\n" +
+                $"Обновлено: {result.UpdatedRecords}\n" +
+                $"Пропущено страниц: {result.FailedPages}\n" +
+                $"Пропущено записей: {result.FailedItems}\n" +
+                $"Карточек без деталей: {result.SkippedDetailRequests}\n" +
+                $"Скачано PDF: {result.DownloadedPdfFiles}\n" +
+                $"Ошибок PDF: {result.FailedPdfFiles}",
+                "CRAWLER",
+                MessageBoxButton.OK,
+                MessageBoxImage.Information);
+        });
+    }
+
+    private async void AddButton_Click(object sender, RoutedEventArgs e)
+    {
+        var dialog = new Dialogs.EditInstrumentWindow(
+            new EditInstrumentWindowViewModel(_viewModel.CreateNewDraft(), true),
+            _filePickerService)
+        {
+            Owner = this
+        };
+
+        if (dialog.ShowDialog() == true)
+        {
+            await ExecuteUiAsync(() => _viewModel.SaveAsync(dialog.ViewModel.Draft, dialog.ViewModel.GetPendingPaths()));
+        }
+    }
+
+    private async void EditButton_Click(object sender, RoutedEventArgs e)
+    {
+        if (_viewModel.SelectedInstrument == null)
+        {
+            return;
+        }
+
+        var dialog = new Dialogs.EditInstrumentWindow(
+            new EditInstrumentWindowViewModel(_viewModel.CreateDraftFromSelected(), false),
+            _filePickerService)
+        {
+            Owner = this
+        };
+
+        if (dialog.ShowDialog() == true)
+        {
+            await ExecuteUiAsync(() => _viewModel.SaveAsync(dialog.ViewModel.Draft, dialog.ViewModel.GetPendingPaths()));
+        }
+    }
+
+    private async void DeleteButton_Click(object sender, RoutedEventArgs e)
+    {
+        if (_viewModel.SelectedInstrument == null)
+        {
+            return;
+        }
+
+        var answer = MessageBox.Show(
+            $"Удалить запись \"{_viewModel.SelectedInstrument.Name}\"?",
+            "CRAWLER",
+            MessageBoxButton.YesNo,
+            MessageBoxImage.Warning);
+
+        if (answer == MessageBoxResult.Yes)
+        {
+            await ExecuteUiAsync(_viewModel.DeleteSelectedAsync);
+        }
+    }
+
+    private async void AddPdfButton_Click(object sender, RoutedEventArgs e)
+    {
+        if (_viewModel.SelectedInstrument == null)
+        {
+            return;
+        }
+
+        var paths = _filePickerService.PickPdfFiles(true);
+        if (paths.Count == 0)
+        {
+            return;
+        }
+
+        await ExecuteUiAsync(() => _viewModel.AddAttachmentsToSelectedAsync(paths));
+    }
+
+    private void OpenAttachmentButton_Click(object sender, RoutedEventArgs e)
+    {
+        _viewModel.OpenAttachment(AttachmentGrid.SelectedItem as PdfAttachment);
+    }
+
+    private async void RemoveAttachmentButton_Click(object sender, RoutedEventArgs e)
+    {
+        var attachment = AttachmentGrid.SelectedItem as PdfAttachment;
+        if (attachment == null)
+        {
+            return;
+        }
+
+        var answer = MessageBox.Show(
+            $"Удалить привязку к PDF \"{attachment.DisplayName}\"?",
+            "CRAWLER",
+            MessageBoxButton.YesNo,
+            MessageBoxImage.Warning);
+
+        if (answer == MessageBoxResult.Yes)
+        {
+            await ExecuteUiAsync(() => _viewModel.RemoveAttachmentAsync(attachment));
+        }
+    }
+
+    private void OpenSourceButton_Click(object sender, RoutedEventArgs e)
+    {
+        _viewModel.OpenSourceUrl();
+    }
+
+    private async void InstrumentGrid_MouseDoubleClick(object sender, MouseButtonEventArgs e)
+    {
+        if (_viewModel.SelectedInstrument != null)
+        {
+            EditButton_Click(sender, e);
+        }
+
+        await Task.CompletedTask;
+    }
+
+    private async void SearchTextBox_KeyDown(object sender, KeyEventArgs e)
+    {
+        if (e.Key == Key.Enter)
+        {
+            e.Handled = true;
+            await ExecuteUiAsync(() => _viewModel.RefreshAsync());
+        }
+    }
+
+    private async Task ExecuteUiAsync(Func<Task> action)
+    {
+        try
+        {
+            await action();
+        }
+        catch (Exception ex)
+        {
+            MessageBox.Show(ex.Message, "CRAWLER", MessageBoxButton.OK, MessageBoxImage.Error);
+        }
+    }
+}
diff --git a/Models/InstrumentModels.cs b/Models/InstrumentModels.cs
new file mode 100644
index 0000000..75cca0f
--- /dev/null
+++ b/Models/InstrumentModels.cs
@@ -0,0 +1,150 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+namespace CRAWLER.Models;
+
+internal sealed class InstrumentSummary
+{
+    public long Id { get; set; }
+    public string RegistryNumber { get; set; }
+    public string Name { get; set; }
+    public string TypeDesignation { get; set; }
+    public string Manufacturer { get; set; }
+    public string VerificationInterval { get; set; }
+    public string SourceSystem { get; set; }
+    public DateTime UpdatedAt { get; set; }
+}
+
+internal sealed class InstrumentRecord
+{
+    public long Id { get; set; }
+    public string RegistryNumber { get; set; }
+    public string Name { get; set; }
+    public string TypeDesignation { get; set; }
+    public string Manufacturer { get; set; }
+    public string VerificationInterval { get; set; }
+    public string CertificateOrSerialNumber { get; set; }
+    public string AllowsBatchVerification { get; set; }
+    public string HasPeriodicVerification { get; set; }
+    public string TypeInfo { get; set; }
+    public string Purpose { get; set; }
+    public string Description { get; set; }
+    public string Software { get; set; }
+    public string MetrologicalCharacteristics { get; set; }
+    public string Completeness { get; set; }
+    public string Verification { get; set; }
+    public string RegulatoryDocuments { get; set; }
+    public string Applicant { get; set; }
+    public string TestCenter { get; set; }
+    public string DetailUrl { get; set; }
+    public string SourceSystem { get; set; } = "Manual";
+    public DateTime? LastImportedAt { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime UpdatedAt { get; set; }
+    public List<PdfAttachment> Attachments { get; set; } = new List<PdfAttachment>();
+
+    public InstrumentRecord Clone()
+    {
+        var copy = (InstrumentRecord)MemberwiseClone();
+        copy.Attachments = new List<PdfAttachment>();
+
+        foreach (var attachment in Attachments)
+        {
+            copy.Attachments.Add(attachment.Clone());
+        }
+
+        return copy;
+    }
+}
+
+internal sealed class PdfAttachment
+{
+    public long Id { get; set; }
+    public long InstrumentId { get; set; }
+    public string Kind { get; set; }
+    public string Title { get; set; }
+    public string SourceUrl { get; set; }
+    public string LocalPath { get; set; }
+    public bool IsManual { get; set; }
+    public DateTime CreatedAt { get; set; }
+
+    public string DisplayName
+    {
+        get
+        {
+            if (!string.IsNullOrWhiteSpace(Title))
+            {
+                return Title;
+            }
+
+            if (!string.IsNullOrWhiteSpace(LocalPath))
+            {
+                return Path.GetFileName(LocalPath);
+            }
+
+            return SourceUrl ?? string.Empty;
+        }
+    }
+
+    public PdfAttachment Clone()
+    {
+        return (PdfAttachment)MemberwiseClone();
+    }
+}
+
+internal sealed class PendingPdfFile
+{
+    public string SourcePath { get; set; }
+    public string DisplayName { get; set; }
+}
+
+internal sealed class CatalogListItem
+{
+    public string RegistryNumber { get; set; }
+    public string Name { get; set; }
+    public string TypeDesignation { get; set; }
+    public string Manufacturer { get; set; }
+    public string VerificationInterval { get; set; }
+    public string CertificateOrSerialNumber { get; set; }
+    public string DetailUrl { get; set; }
+    public string DescriptionTypePdfUrl { get; set; }
+    public string MethodologyPdfUrl { get; set; }
+}
+
+internal sealed class ParsedInstrumentDetails
+{
+    public string RegistryNumber { get; set; }
+    public string Name { get; set; }
+    public string TypeDesignation { get; set; }
+    public string Manufacturer { get; set; }
+    public string VerificationInterval { get; set; }
+    public string CertificateOrSerialNumber { get; set; }
+    public string AllowsBatchVerification { get; set; }
+    public string HasPeriodicVerification { get; set; }
+    public string TypeInfo { get; set; }
+    public string Purpose { get; set; }
+    public string Description { get; set; }
+    public string Software { get; set; }
+    public string MetrologicalCharacteristics { get; set; }
+    public string Completeness { get; set; }
+    public string Verification { get; set; }
+    public string RegulatoryDocuments { get; set; }
+    public string Applicant { get; set; }
+    public string TestCenter { get; set; }
+    public string DescriptionTypePdfUrl { get; set; }
+    public string MethodologyPdfUrl { get; set; }
+}
+
+internal sealed class SyncResult
+{
+    public int PagesScanned { get; set; }
+    public int ProcessedItems { get; set; }
+    public int AddedRecords { get; set; }
+    public int UpdatedRecords { get; set; }
+    public int DownloadedPdfFiles { get; set; }
+    public int FailedPdfFiles { get; set; }
+    public int FailedPages { get; set; }
+    public int FailedItems { get; set; }
+    public int SkippedDetailRequests { get; set; }
+}
diff --git a/Parsing/CatalogPageParser.cs b/Parsing/CatalogPageParser.cs
new file mode 100644
index 0000000..148e379
--- /dev/null
+++ b/Parsing/CatalogPageParser.cs
@@ -0,0 +1,86 @@
+using System;
+using System.Collections.Generic;
+using CRAWLER.Models;
+using HtmlAgilityPack;
+
+namespace CRAWLER.Parsing;
+
+internal sealed class CatalogPageParser
+{
+    public IReadOnlyList<CatalogListItem> Parse(string html, string baseUrl)
+    {
+        var document = new HtmlDocument();
+        document.LoadHtml(html ?? string.Empty);
+
+        var items = new List<CatalogListItem>();
+        var nodes = document.DocumentNode.SelectNodes("//div[contains(concat(' ', normalize-space(@class), ' '), ' sivreestre ')]");
+        if (nodes == null)
+        {
+            return items;
+        }
+
+        foreach (var node in nodes)
+        {
+            var item = new CatalogListItem
+            {
+                RegistryNumber = ReadBlockValue(node, "№ в госреестре"),
+                Name = ReadBlockValue(node, "Наименование"),
+                TypeDesignation = ReadBlockValue(node, "Тип"),
+                Manufacturer = ReadBlockValue(node, "Производитель"),
+                VerificationInterval = ReadBlockValue(node, "МПИ"),
+                CertificateOrSerialNumber = ReadBlockValue(node, "Cвидетельство завод. номер")
+                    ?? ReadBlockValue(node, "Свидетельство завод. номер"),
+                DetailUrl = ReadDetailUrl(node, baseUrl),
+                DescriptionTypePdfUrl = ReadPdfUrl(node, "/prof/opisanie/", baseUrl),
+                MethodologyPdfUrl = ReadPdfUrl(node, "/prof/metodiki/", baseUrl)
+            };
+
+            if (!string.IsNullOrWhiteSpace(item.RegistryNumber) || !string.IsNullOrWhiteSpace(item.Name))
+            {
+                items.Add(item);
+            }
+        }
+
+        return items;
+    }
+
+    private static string ReadBlockValue(HtmlNode root, string header)
+    {
+        var block = FindBlockByHeader(root, header);
+        return HtmlParsingHelpers.ExtractNodeTextExcludingChildParagraph(block);
+    }
+
+    private static HtmlNode FindBlockByHeader(HtmlNode root, string header)
+    {
+        var blocks = root.SelectNodes("./div");
+        if (blocks == null)
+        {
+            return null;
+        }
+
+        foreach (var block in blocks)
+        {
+            var paragraph = block.SelectSingleNode("./p");
+            var label = HtmlParsingHelpers.NormalizeLabel(paragraph?.InnerText);
+            if (string.Equals(label, header, StringComparison.OrdinalIgnoreCase))
+            {
+                return block;
+            }
+        }
+
+        return null;
+    }
+
+    private static string ReadDetailUrl(HtmlNode root, string baseUrl)
+    {
+        var link = root.SelectSingleNode(".//div[contains(@class,'resulttable6')]/a[1]")
+                   ?? root.SelectSingleNode(".//div[contains(@class,'resulttable4')]/a[1]");
+        return HtmlParsingHelpers.MakeAbsoluteUrl(baseUrl, link?.GetAttributeValue("href", null));
+    }
+
+    private static string ReadPdfUrl(HtmlNode root, string marker, string baseUrl)
+    {
+        var link = root.SelectSingleNode($".//a[contains(@href,'{marker}')]");
+        return HtmlParsingHelpers.MakeAbsoluteUrl(baseUrl, link?.GetAttributeValue("href", null));
+    }
+}
diff --git a/Parsing/DetailPageParser.cs b/Parsing/DetailPageParser.cs
new file mode 100644
index 0000000..4568c88
--- /dev/null
+++ b/Parsing/DetailPageParser.cs
@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using CRAWLER.Models;
+using HtmlAgilityPack;
+
+namespace CRAWLER.Parsing;
+
+internal sealed class DetailPageParser
+{
+    public ParsedInstrumentDetails Parse(string html, string baseUrl)
+    {
+        var document = new HtmlDocument();
+        document.LoadHtml(html ?? string.Empty);
+
+        var rows = document.DocumentNode.SelectNodes("//table[contains(@class,'resulttable1')]//tr");
+        var values = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        if (rows != null)
+        {
+            foreach (var row in rows)
+            {
+                var cells = row.SelectNodes("./td");
+                if (cells == null || cells.Count < 2)
+                {
+                    continue;
+                }
+
+                var label = HtmlParsingHelpers.NormalizeLabel(cells[0].InnerText);
+                var value = HtmlParsingHelpers.NormalizeWhitespace(cells[1].InnerText);
+                if (!string.IsNullOrWhiteSpace(label))
+                {
+                    values[label] = value;
+                }
+            }
+        }
+
+        return new ParsedInstrumentDetails
+        {
+            RegistryNumber = Get(values, "Номер в госреестре"),
+            Name = Get(values, "Наименование"),
+            TypeDesignation = Get(values, "Обозначение типа"),
+            Manufacturer = Get(values, "Производитель"),
+            VerificationInterval = Get(values, "Межповерочный интервал (МПИ)"),
+            CertificateOrSerialNumber = Get(values, "Срок свидетельства или заводской номер"),
+            AllowsBatchVerification = Get(values, "Допускается поверка партии"),
+            HasPeriodicVerification = Get(values, "Наличие периодической поверки"),
+            TypeInfo = Get(values, "Сведения о типе"),
+            Purpose = Get(values, "Назначение"),
+            Description = Get(values, "Описание"),
+            Software = Get(values, "Программное обеспечение"),
+            MetrologicalCharacteristics = Get(values, "Метрологические и технические характеристики"),
+            Completeness = Get(values, "Комплектность"),
+            Verification = Get(values, "Поверка"),
+            RegulatoryDocuments = Get(values, "Нормативные и технические документы"),
+            Applicant = Get(values, "Заявитель"),
+            TestCenter = Get(values, "Испытательный центр"),
+            DescriptionTypePdfUrl = HtmlParsingHelpers.MakeAbsoluteUrl(baseUrl, document.DocumentNode.SelectSingleNode("//a[contains(@href,'/prof/opisanie/')]")?.GetAttributeValue("href", null)),
+            MethodologyPdfUrl = HtmlParsingHelpers.MakeAbsoluteUrl(baseUrl, document.DocumentNode.SelectSingleNode("//a[contains(@href,'/prof/metodiki/')]")?.GetAttributeValue("href", null))
+        };
+    }
+
+    private static string Get(IDictionary<string, string> values, string key)
+    {
+        return values.TryGetValue(key, out var value) ? value : null;
+    }
+}
diff --git a/Parsing/HtmlParsingHelpers.cs b/Parsing/HtmlParsingHelpers.cs
new file mode 100644
index 0000000..0a15700
--- /dev/null
+++ b/Parsing/HtmlParsingHelpers.cs
@@ -0,0 +1,64 @@
+using System;
+using System.Text.RegularExpressions;
+using HtmlAgilityPack;
+
+namespace CRAWLER.Parsing;
+
+internal static class HtmlParsingHelpers
+{
+    public static string NormalizeWhitespace(string value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            return null;
+        }
+
+        var decoded = HtmlEntity.DeEntitize(value);
+        decoded = decoded.Replace('\u00A0', ' ');
+        decoded = Regex.Replace(decoded, @"\s+", " ");
+        return decoded.Trim();
+    }
+
+    public static string NormalizeLabel(string value)
+    {
+        return NormalizeWhitespace(value)
+            ?.Replace(" :", ":")
+            .Trim(':', ' ');
+    }
+
+    public static string MakeAbsoluteUrl(string baseUrl, string urlOrPath)
+    {
+        if (string.IsNullOrWhiteSpace(urlOrPath))
+        {
+            return null;
+        }
+
+        if (Uri.TryCreate(urlOrPath, UriKind.Absolute, out var absoluteUri))
+        {
+            return absoluteUri.ToString();
+        }
+
+        var baseUri = new Uri(baseUrl.TrimEnd('/') + "/");
+        return new Uri(baseUri, urlOrPath.TrimStart('/')).ToString();
+    }
+
+    public static string ExtractNodeTextExcludingChildParagraph(HtmlNode node)
+    {
+        if (node == null)
+        {
+            return null;
+        }
+
+        var clone = node.CloneNode(true);
+        var paragraphs = clone.SelectNodes("./p");
+        if (paragraphs != null)
+        {
+            foreach (var paragraph in paragraphs)
+            {
+                paragraph.Remove();
+            }
+        }
+
+        return NormalizeWhitespace(clone.InnerText);
+    }
+}
diff --git a/SampleData/catalog-page-sample.html b/SampleData/catalog-page-sample.html
new file mode 100644
index 0000000..0bc41fa
--- /dev/null
+++ b/SampleData/catalog-page-sample.html
@@ -0,0 +1,31 @@
+<div class="resulttable11">
+    <div class="sivreestre">
+        <div class="resulttable4">
+            <p>№ в госреестре</p>
+            <a href="/poverka/gosreestr_sredstv_izmereniy/1427888/Raskhodomery-schetchiki_elektromagnitnyye">97957-26</a>
+        </div>
+        <div class="resulttable6">
+            <p>Наименование</p>
+            <a href="/poverka/gosreestr_sredstv_izmereniy/1427888/Raskhodomery-schetchiki_elektromagnitnyye">Расходомеры-счетчики электромагнитные</a>
+        </div>
+        <div class="resulttable4">
+            <p>Тип</p>Счетовод
+        </div>
+        <div class="resulttable4">
+            <p>Описание типа</p>
+            <a rel="nofollow" target="_blank" href="/prof/opisanie/97957-26.pdf">Скачать</a>
+            <p>Методики поверки</p>
+            <a rel="nofollow" target="_blank" href="/prof/metodiki/97957-26.pdf">Скачать</a>
+        </div>
+        <div class="resulttable4">
+            <p>МПИ</p>60 мес.
+        </div>
+        <div class="resulttable4">
+            <p>Cвидетельство<br>завод. номер</p>00033, 00032, 00031, 0003010.03.2031
+        </div>
+        <div class="resulttable6">
+            <p>Производитель</p>
+            <a href="/poverka?view=gosreestr_sredstv_izmereniy&amp;izgotov=test">Общество с ограниченной ответственностью «Производственная фирма «Гидродинамика»</a>
+        </div>
+    </div>
+</div>
diff --git a/SampleData/detail-page-sample.html b/SampleData/detail-page-sample.html
new file mode 100644
index 0000000..72f9859
--- /dev/null
+++ b/SampleData/detail-page-sample.html
@@ -0,0 +1,22 @@
+<table class="resulttable1">
+    <tr><td class="resulttable2">Номер в госреестре</td><td class="resulttable"><div class="alllinks"><div class="onelink">97957-26</div></div></td></tr>
+    <tr><td class="resulttable2">Наименование</td><td class="resulttable">Расходомеры-счетчики электромагнитные</td></tr>
+    <tr><td class="resulttable2">Обозначение типа</td><td class="resulttable">Счетовод</td></tr>
+    <tr><td class="resulttable2">Производитель</td><td class="resulttable">Общество с ограниченной ответственностью «Производственная фирма «Гидродинамика»</td></tr>
+    <tr><td class="resulttable2">Описание типа</td><td class="resulttable"><a rel="nofollow" target="_blank" href="/prof/opisanie/97957-26.pdf">Скачать</a></td></tr>
+    <tr><td class="resulttable2">Методика поверки</td><td class="resulttable"><a rel="nofollow" target="_blank" href="/prof/metodiki/97957-26.pdf">Скачать</a></td></tr>
+    <tr><td class="resulttable2">Межповерочный интервал (МПИ)</td><td class="resulttable">60 мес.</td></tr>
+    <tr><td class="resulttable2">Допускается поверка партии</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Наличие периодической поверки</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Сведения о типе</td><td class="resulttable">Заводской номер</td></tr>
+    <tr><td class="resulttable2">Срок свидетельства или заводской номер</td><td class="resulttable">10.03.2031</td></tr>
+    <tr><td class="resulttable2">Назначение</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Описание</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Программное обеспечение</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Метрологические и технические характеристики</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Комплектность</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Поверка</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Нормативные и технические документы</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Заявитель</td><td class="resulttable"></td></tr>
+    <tr><td class="resulttable2">Испытательный центр</td><td class="resulttable"></td></tr>
+</table>
diff --git a/Services/DatabaseInitializer.cs b/Services/DatabaseInitializer.cs
new file mode 100644
index 0000000..ba853db
--- /dev/null
+++ b/Services/DatabaseInitializer.cs
@@ -0,0 +1,141 @@
+using Microsoft.Data.SqlClient;
+
+namespace CRAWLER.Services;
+
+internal sealed class DatabaseInitializer
+{
+    private readonly IDatabaseConnectionFactory _connectionFactory;
+
+    public DatabaseInitializer(IDatabaseConnectionFactory connectionFactory)
+    {
+        _connectionFactory = connectionFactory;
+    }
+
+    public async Task EnsureCreatedAsync(CancellationToken cancellationToken)
+    {
+        await EnsureDatabaseExistsAsync(cancellationToken);
+        await EnsureSchemaAsync(cancellationToken);
+    }
+
+    private async Task EnsureDatabaseExistsAsync(CancellationToken cancellationToken)
+    {
+        await using var connection = _connectionFactory.CreateMasterConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        var safeDatabaseName = _connectionFactory.Options.Database.Replace("]", "]]");
+        var sql = $@"
+IF DB_ID(N'{safeDatabaseName}') IS NULL
+BEGIN
+    CREATE DATABASE [{safeDatabaseName}];
+END";
+
+        await using var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+        await command.ExecuteNonQueryAsync(cancellationToken);
+    }
+
+    private async Task EnsureSchemaAsync(CancellationToken cancellationToken)
+    {
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        var scripts = new[]
+        {
+            @"
+IF OBJECT_ID(N'dbo.Instruments', N'U') IS NULL
+BEGIN
+    CREATE TABLE dbo.Instruments
+    (
+        Id BIGINT IDENTITY(1,1) NOT NULL CONSTRAINT PK_Instruments PRIMARY KEY,
+        RegistryNumber NVARCHAR(64) NULL,
+        Name NVARCHAR(512) NOT NULL,
+        TypeDesignation NVARCHAR(512) NULL,
+        Manufacturer NVARCHAR(2000) NULL,
+        VerificationInterval NVARCHAR(512) NULL,
+        CertificateOrSerialNumber NVARCHAR(512) NULL,
+        AllowsBatchVerification NVARCHAR(256) NULL,
+        HasPeriodicVerification NVARCHAR(256) NULL,
+        TypeInfo NVARCHAR(256) NULL,
+        Purpose NVARCHAR(MAX) NULL,
+        Description NVARCHAR(MAX) NULL,
+        Software NVARCHAR(MAX) NULL,
+        MetrologicalCharacteristics NVARCHAR(MAX) NULL,
+        Completeness NVARCHAR(MAX) NULL,
+        Verification NVARCHAR(MAX) NULL,
+        RegulatoryDocuments NVARCHAR(MAX) NULL,
+        Applicant NVARCHAR(MAX) NULL,
+        TestCenter NVARCHAR(MAX) NULL,
+        DetailUrl NVARCHAR(1024) NULL,
+        SourceSystem NVARCHAR(64) NOT NULL CONSTRAINT DF_Instruments_SourceSystem DEFAULT N'Manual',
+        LastImportedAt DATETIME2 NULL,
+        CreatedAt DATETIME2 NOT NULL CONSTRAINT DF_Instruments_CreatedAt DEFAULT SYSUTCDATETIME(),
+        UpdatedAt DATETIME2 NOT NULL CONSTRAINT DF_Instruments_UpdatedAt DEFAULT SYSUTCDATETIME()
+    );
+END",
+            @"
+IF NOT EXISTS (
+    SELECT 1
+    FROM sys.indexes
+    WHERE name = N'UX_Instruments_RegistryNumber'
+      AND object_id = OBJECT_ID(N'dbo.Instruments')
+)
+BEGIN
+    CREATE UNIQUE INDEX UX_Instruments_RegistryNumber
+        ON dbo.Instruments (RegistryNumber)
+        WHERE RegistryNumber IS NOT NULL AND RegistryNumber <> N'';
+END",
+            @"
+IF OBJECT_ID(N'dbo.PdfAttachments', N'U') IS NULL
+BEGIN
+    CREATE TABLE dbo.PdfAttachments
+    (
+        Id BIGINT IDENTITY(1,1) NOT NULL CONSTRAINT PK_PdfAttachments PRIMARY KEY,
+        InstrumentId BIGINT NOT NULL,
+        Kind NVARCHAR(128) NOT NULL,
+        Title NVARCHAR(256) NULL,
+        SourceUrl NVARCHAR(1024) NULL,
+        LocalPath NVARCHAR(1024) NULL,
+        IsManual BIT NOT NULL CONSTRAINT DF_PdfAttachments_IsManual DEFAULT (0),
+        CreatedAt DATETIME2 NOT NULL CONSTRAINT DF_PdfAttachments_CreatedAt DEFAULT SYSUTCDATETIME(),
+        CONSTRAINT FK_PdfAttachments_Instruments
+            FOREIGN KEY (InstrumentId) REFERENCES dbo.Instruments(Id)
+            ON DELETE CASCADE
+    );
+END",
+            @"
+IF NOT EXISTS (
+    SELECT 1
+    FROM sys.indexes
+    WHERE name = N'IX_PdfAttachments_InstrumentId'
+      AND object_id = OBJECT_ID(N'dbo.PdfAttachments')
+)
+BEGIN
+    CREATE INDEX IX_PdfAttachments_InstrumentId
+        ON dbo.PdfAttachments (InstrumentId, CreatedAt DESC);
+END",
+            @"
+IF NOT EXISTS (
+    SELECT 1
+    FROM sys.indexes
+    WHERE name = N'UX_PdfAttachments_InstrumentId_SourceUrl'
+      AND object_id = OBJECT_ID(N'dbo.PdfAttachments')
+)
+BEGIN
+    CREATE UNIQUE INDEX UX_PdfAttachments_InstrumentId_SourceUrl
+        ON dbo.PdfAttachments (InstrumentId, SourceUrl)
+        WHERE SourceUrl IS NOT NULL AND SourceUrl <> N'';
+END"
+        };
+
+        foreach (var script in scripts)
+        {
+            await using var command = new SqlCommand(script, connection)
+            {
+                CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+            };
+            await command.ExecuteNonQueryAsync(cancellationToken);
+        }
+    }
+}
diff --git a/Services/FilePickerService.cs b/Services/FilePickerService.cs
new file mode 100644
index 0000000..13797ed
--- /dev/null
+++ b/Services/FilePickerService.cs
@@ -0,0 +1,26 @@
+using Microsoft.Win32;
+
+namespace CRAWLER.Services;
+
+internal interface IFilePickerService
+{
+    IReadOnlyList<string> PickPdfFiles(bool multiselect);
+}
+
+internal sealed class FilePickerService : IFilePickerService
+{
+    public IReadOnlyList<string> PickPdfFiles(bool multiselect)
+    {
+        var dialog = new OpenFileDialog
+        {
+            Filter = "PDF (*.pdf)|*.pdf",
+            Multiselect = multiselect,
+            CheckFileExists = true,
+            CheckPathExists = true
+        };
+
+        return dialog.ShowDialog() == true
+            ? dialog.FileNames
+            : Array.Empty<string>();
+    }
+}
diff --git a/Services/InstrumentCatalogService.cs b/Services/InstrumentCatalogService.cs
new file mode 100644
index 0000000..31f3f72
--- /dev/null
+++ b/Services/InstrumentCatalogService.cs
@@ -0,0 +1,306 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using CRAWLER.Models;
+using CRAWLER.Parsing;
+
+namespace CRAWLER.Services;
+
+internal sealed class InstrumentCatalogService
+{
+    private readonly CatalogPageParser _catalogPageParser;
+    private readonly DatabaseInitializer _databaseInitializer;
+    private readonly DetailPageParser _detailPageParser;
+    private readonly InstrumentRepository _repository;
+    private readonly KtoPoveritClient _client;
+    private readonly PdfStorageService _pdfStorageService;
+
+    public InstrumentCatalogService(
+        DatabaseInitializer databaseInitializer,
+        InstrumentRepository repository,
+        CatalogPageParser catalogPageParser,
+        DetailPageParser detailPageParser,
+        KtoPoveritClient client,
+        PdfStorageService pdfStorageService)
+    {
+        _databaseInitializer = databaseInitializer;
+        _repository = repository;
+        _catalogPageParser = catalogPageParser;
+        _detailPageParser = detailPageParser;
+        _client = client;
+        _pdfStorageService = pdfStorageService;
+    }
+
+    public int DefaultPagesToScan
+    {
+        get { return Math.Max(1, _client.Options.DefaultPagesToScan); }
+    }
+
+    public async Task InitializeAsync(CancellationToken cancellationToken)
+    {
+        await _databaseInitializer.EnsureCreatedAsync(cancellationToken);
+    }
+
+    public Task<IReadOnlyList<InstrumentSummary>> SearchAsync(string searchText, CancellationToken cancellationToken)
+    {
+        return _repository.SearchAsync(searchText, cancellationToken);
+    }
+
+    public Task<InstrumentRecord> GetByIdAsync(long id, CancellationToken cancellationToken)
+    {
+        return _repository.GetByIdAsync(id, cancellationToken);
+    }
+
+    public async Task<long> SaveInstrumentAsync(InstrumentRecord record, IEnumerable<string> pendingPdfPaths, CancellationToken cancellationToken)
+    {
+        var id = await _repository.SaveAsync(record, cancellationToken);
+
+        if (pendingPdfPaths != null)
+        {
+            foreach (var sourcePath in pendingPdfPaths.Where(path => !string.IsNullOrWhiteSpace(path)))
+            {
+                var localPath = await _pdfStorageService.CopyFromLocalAsync(sourcePath, record.RegistryNumber, Path.GetFileNameWithoutExtension(sourcePath), cancellationToken);
+                await _repository.SaveAttachmentAsync(new PdfAttachment
+                {
+                    InstrumentId = id,
+                    Kind = "Ручной PDF",
+                    Title = Path.GetFileNameWithoutExtension(sourcePath),
+                    LocalPath = localPath,
+                    SourceUrl = null,
+                    IsManual = true
+                }, cancellationToken);
+            }
+        }
+
+        return id;
+    }
+
+    public async Task DeleteInstrumentAsync(InstrumentRecord record, CancellationToken cancellationToken)
+    {
+        if (record == null)
+        {
+            return;
+        }
+
+        foreach (var attachment in record.Attachments)
+        {
+            _pdfStorageService.TryDelete(attachment.LocalPath);
+        }
+
+        await _repository.DeleteInstrumentAsync(record.Id, cancellationToken);
+    }
+
+    public async Task RemoveAttachmentAsync(PdfAttachment attachment, CancellationToken cancellationToken)
+    {
+        if (attachment == null)
+        {
+            return;
+        }
+
+        _pdfStorageService.TryDelete(attachment.LocalPath);
+        await _repository.DeleteAttachmentAsync(attachment.Id, cancellationToken);
+    }
+
+    public async Task<IReadOnlyList<PdfAttachment>> AddManualAttachmentsAsync(long instrumentId, string registryNumber, IEnumerable<string> sourcePaths, CancellationToken cancellationToken)
+    {
+        if (sourcePaths == null)
+        {
+            return Array.Empty<PdfAttachment>();
+        }
+
+        var added = new List<PdfAttachment>();
+        foreach (var sourcePath in sourcePaths.Where(path => !string.IsNullOrWhiteSpace(path)))
+        {
+            var localPath = await _pdfStorageService.CopyFromLocalAsync(sourcePath, registryNumber, Path.GetFileNameWithoutExtension(sourcePath), cancellationToken);
+            var attachment = new PdfAttachment
+            {
+                InstrumentId = instrumentId,
+                Kind = "Ручной PDF",
+                Title = Path.GetFileNameWithoutExtension(sourcePath),
+                SourceUrl = null,
+                LocalPath = localPath,
+                IsManual = true
+            };
+
+            await _repository.SaveAttachmentAsync(attachment, cancellationToken);
+            added.Add(attachment);
+        }
+
+        return added;
+    }
+
+    public async Task<SyncResult> SyncFromSiteAsync(int pagesToScan, IProgress<string> progress, CancellationToken cancellationToken)
+    {
+        var result = new SyncResult();
+        var totalPages = Math.Max(1, pagesToScan);
+
+        for (var page = 1; page <= totalPages; page++)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            progress?.Report($"Чтение страницы {page}...");
+
+            IReadOnlyList<CatalogListItem> items;
+            try
+            {
+                var catalogHtml = await _client.GetStringAsync(_client.BuildCatalogPageUrl(page), cancellationToken);
+                items = _catalogPageParser.Parse(catalogHtml, _client.Options.BaseUrl);
+                result.PagesScanned++;
+            }
+            catch (Exception ex)
+            {
+                result.FailedPages++;
+                progress?.Report($"Страница {page} пропущена: {ex.Message}");
+                continue;
+            }
+
+            foreach (var item in items)
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+                progress?.Report($"Обработка {item.RegistryNumber ?? item.Name}...");
+
+                try
+                {
+                    var existingId = await _repository.FindInstrumentIdByRegistryNumberAsync(item.RegistryNumber, cancellationToken);
+                    var existing = existingId.HasValue
+                        ? await _repository.GetByIdAsync(existingId.Value, cancellationToken)
+                        : null;
+
+                    ParsedInstrumentDetails details = null;
+                    if (!string.IsNullOrWhiteSpace(item.DetailUrl))
+                    {
+                        try
+                        {
+                            var detailHtml = await _client.GetStringAsync(item.DetailUrl, cancellationToken);
+                            details = _detailPageParser.Parse(detailHtml, _client.Options.BaseUrl);
+                        }
+                        catch
+                        {
+                            result.SkippedDetailRequests++;
+                        }
+                    }
+
+                    var merged = Merge(existing, item, details);
+                    merged.Id = existing?.Id ?? 0;
+                    merged.SourceSystem = "KtoPoverit";
+                    merged.DetailUrl = item.DetailUrl ?? existing?.DetailUrl;
+                    merged.LastImportedAt = DateTime.UtcNow;
+
+                    var savedId = await _repository.SaveAsync(merged, cancellationToken);
+                    result.ProcessedItems++;
+                    if (existing == null)
+                    {
+                        result.AddedRecords++;
+                    }
+                    else
+                    {
+                        result.UpdatedRecords++;
+                    }
+
+                    await SyncAttachmentAsync(savedId, merged.RegistryNumber, "Описание типа", details?.DescriptionTypePdfUrl ?? item.DescriptionTypePdfUrl, result, cancellationToken);
+                    await SyncAttachmentAsync(savedId, merged.RegistryNumber, "Методика поверки", details?.MethodologyPdfUrl ?? item.MethodologyPdfUrl, result, cancellationToken);
+
+                    if (_client.Options.RequestDelayMilliseconds > 0)
+                    {
+                        await Task.Delay(_client.Options.RequestDelayMilliseconds, cancellationToken);
+                    }
+                }
+                catch (Exception ex)
+                {
+                    result.FailedItems++;
+                    progress?.Report($"Запись {item.RegistryNumber ?? item.Name} пропущена: {ex.Message}");
+                }
+            }
+        }
+
+        progress?.Report($"Готово: страниц {result.PagesScanned}, записей {result.ProcessedItems}, проблемных записей {result.FailedItems}.");
+        return result;
+    }
+
+    private async Task SyncAttachmentAsync(long instrumentId, string registryNumber, string title, string sourceUrl, SyncResult result, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(sourceUrl))
+        {
+            return;
+        }
+
+        var existing = await _repository.FindAttachmentBySourceUrlAsync(instrumentId, sourceUrl, cancellationToken);
+        if (existing != null && !string.IsNullOrWhiteSpace(existing.LocalPath) && File.Exists(existing.LocalPath))
+        {
+            return;
+        }
+
+        try
+        {
+            var localPath = await _pdfStorageService.DownloadAsync(sourceUrl, registryNumber, title, cancellationToken);
+            var attachment = existing ?? new PdfAttachment
+            {
+                InstrumentId = instrumentId,
+                IsManual = false
+            };
+
+            attachment.Kind = title;
+            attachment.Title = title;
+            attachment.SourceUrl = sourceUrl;
+            attachment.LocalPath = localPath;
+
+            await _repository.SaveAttachmentAsync(attachment, cancellationToken);
+            result.DownloadedPdfFiles++;
+        }
+        catch
+        {
+            result.FailedPdfFiles++;
+
+            if (existing == null)
+            {
+                await _repository.SaveAttachmentAsync(new PdfAttachment
+                {
+                    InstrumentId = instrumentId,
+                    Kind = title,
+                    Title = title,
+                    SourceUrl = sourceUrl,
+                    LocalPath = null,
+                    IsManual = false
+                }, cancellationToken);
+            }
+        }
+    }
+
+    private static InstrumentRecord Merge(InstrumentRecord existing, CatalogListItem item, ParsedInstrumentDetails details)
+    {
+        var result = existing?.Clone() ?? new InstrumentRecord();
+
+        result.RegistryNumber = Prefer(details?.RegistryNumber, item?.RegistryNumber, existing?.RegistryNumber);
+        result.Name = Prefer(details?.Name, item?.Name, existing?.Name) ?? "Без названия";
+        result.TypeDesignation = Prefer(details?.TypeDesignation, item?.TypeDesignation, existing?.TypeDesignation);
+        result.Manufacturer = Prefer(details?.Manufacturer, item?.Manufacturer, existing?.Manufacturer);
+        result.VerificationInterval = Prefer(details?.VerificationInterval, item?.VerificationInterval, existing?.VerificationInterval);
+        result.CertificateOrSerialNumber = Prefer(details?.CertificateOrSerialNumber, item?.CertificateOrSerialNumber, existing?.CertificateOrSerialNumber);
+        result.AllowsBatchVerification = Prefer(details?.AllowsBatchVerification, existing?.AllowsBatchVerification);
+        result.HasPeriodicVerification = Prefer(details?.HasPeriodicVerification, existing?.HasPeriodicVerification);
+        result.TypeInfo = Prefer(details?.TypeInfo, existing?.TypeInfo);
+        result.Purpose = Prefer(details?.Purpose, existing?.Purpose);
+        result.Description = Prefer(details?.Description, existing?.Description);
+        result.Software = Prefer(details?.Software, existing?.Software);
+        result.MetrologicalCharacteristics = Prefer(details?.MetrologicalCharacteristics, existing?.MetrologicalCharacteristics);
+        result.Completeness = Prefer(details?.Completeness, existing?.Completeness);
+        result.Verification = Prefer(details?.Verification, existing?.Verification);
+        result.RegulatoryDocuments = Prefer(details?.RegulatoryDocuments, existing?.RegulatoryDocuments);
+        result.Applicant = Prefer(details?.Applicant, existing?.Applicant);
+        result.TestCenter = Prefer(details?.TestCenter, existing?.TestCenter);
+        return result;
+    }
+
+    private static string Prefer(params string[] values)
+    {
+        foreach (var value in values)
+        {
+            if (!string.IsNullOrWhiteSpace(value))
+            {
+                return value.Trim();
+            }
+        }
+
+        return null;
+    }
+}
diff --git a/Services/InstrumentRepository.cs b/Services/InstrumentRepository.cs
new file mode 100644
index 0000000..e32ef3c
--- /dev/null
+++ b/Services/InstrumentRepository.cs
@@ -0,0 +1,526 @@
+using CRAWLER.Models;
+using Microsoft.Data.SqlClient;
+
+namespace CRAWLER.Services;
+
+internal sealed class InstrumentRepository
+{
+    private readonly IDatabaseConnectionFactory _connectionFactory;
+
+    public InstrumentRepository(IDatabaseConnectionFactory connectionFactory)
+    {
+        _connectionFactory = connectionFactory;
+    }
+
+    public async Task<IReadOnlyList<InstrumentSummary>> SearchAsync(string searchText, CancellationToken cancellationToken)
+    {
+        var items = new List<InstrumentSummary>();
+        var hasFilter = !string.IsNullOrWhiteSpace(searchText);
+
+        const string sql = @"
+SELECT TOP (500)
+    Id,
+    RegistryNumber,
+    Name,
+    TypeDesignation,
+    Manufacturer,
+    VerificationInterval,
+    SourceSystem,
+    UpdatedAt
+FROM dbo.Instruments
+WHERE @Search IS NULL
+   OR RegistryNumber LIKE @Like
+   OR Name LIKE @Like
+   OR TypeDesignation LIKE @Like
+   OR Manufacturer LIKE @Like
+ORDER BY
+    CASE WHEN RegistryNumber IS NULL OR RegistryNumber = N'' THEN 1 ELSE 0 END,
+    RegistryNumber DESC,
+    UpdatedAt DESC;";
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        await using var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+        command.Parameters.AddWithValue("@Search", hasFilter ? searchText.Trim() : DBNull.Value);
+        command.Parameters.AddWithValue("@Like", hasFilter ? $"%{searchText.Trim()}%" : DBNull.Value);
+
+        await using var reader = await command.ExecuteReaderAsync(cancellationToken);
+        while (await reader.ReadAsync(cancellationToken))
+        {
+            items.Add(new InstrumentSummary
+            {
+                Id = reader.GetInt64(0),
+                RegistryNumber = GetString(reader, 1),
+                Name = GetString(reader, 2),
+                TypeDesignation = GetString(reader, 3),
+                Manufacturer = GetString(reader, 4),
+                VerificationInterval = GetString(reader, 5),
+                SourceSystem = GetString(reader, 6),
+                UpdatedAt = reader.GetDateTime(7)
+            });
+        }
+
+        return items;
+    }
+
+    public async Task<InstrumentRecord> GetByIdAsync(long id, CancellationToken cancellationToken)
+    {
+        const string sql = @"
+SELECT
+    Id,
+    RegistryNumber,
+    Name,
+    TypeDesignation,
+    Manufacturer,
+    VerificationInterval,
+    CertificateOrSerialNumber,
+    AllowsBatchVerification,
+    HasPeriodicVerification,
+    TypeInfo,
+    Purpose,
+    Description,
+    Software,
+    MetrologicalCharacteristics,
+    Completeness,
+    Verification,
+    RegulatoryDocuments,
+    Applicant,
+    TestCenter,
+    DetailUrl,
+    SourceSystem,
+    LastImportedAt,
+    CreatedAt,
+    UpdatedAt
+FROM dbo.Instruments
+WHERE Id = @Id;";
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        await using var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+        command.Parameters.AddWithValue("@Id", id);
+
+        InstrumentRecord item = null;
+        await using (var reader = await command.ExecuteReaderAsync(cancellationToken))
+        {
+            if (await reader.ReadAsync(cancellationToken))
+            {
+                item = new InstrumentRecord
+                {
+                    Id = reader.GetInt64(0),
+                    RegistryNumber = GetString(reader, 1),
+                    Name = GetString(reader, 2),
+                    TypeDesignation = GetString(reader, 3),
+                    Manufacturer = GetString(reader, 4),
+                    VerificationInterval = GetString(reader, 5),
+                    CertificateOrSerialNumber = GetString(reader, 6),
+                    AllowsBatchVerification = GetString(reader, 7),
+                    HasPeriodicVerification = GetString(reader, 8),
+                    TypeInfo = GetString(reader, 9),
+                    Purpose = GetString(reader, 10),
+                    Description = GetString(reader, 11),
+                    Software = GetString(reader, 12),
+                    MetrologicalCharacteristics = GetString(reader, 13),
+                    Completeness = GetString(reader, 14),
+                    Verification = GetString(reader, 15),
+                    RegulatoryDocuments = GetString(reader, 16),
+                    Applicant = GetString(reader, 17),
+                    TestCenter = GetString(reader, 18),
+                    DetailUrl = GetString(reader, 19),
+                    SourceSystem = GetString(reader, 20),
+                    LastImportedAt = reader.IsDBNull(21) ? (DateTime?)null : reader.GetDateTime(21),
+                    CreatedAt = reader.GetDateTime(22),
+                    UpdatedAt = reader.GetDateTime(23)
+                };
+            }
+        }
+
+        if (item == null)
+        {
+            return null;
+        }
+
+        item.Attachments = (await GetAttachmentsAsync(connection, id, cancellationToken)).ToList();
+        return item;
+    }
+
+    public async Task<long?> FindInstrumentIdByRegistryNumberAsync(string registryNumber, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(registryNumber))
+        {
+            return null;
+        }
+
+        const string sql = "SELECT Id FROM dbo.Instruments WHERE RegistryNumber = @RegistryNumber;";
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        await using var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+        command.Parameters.AddWithValue("@RegistryNumber", registryNumber.Trim());
+
+        var result = await command.ExecuteScalarAsync(cancellationToken);
+        if (result == null || result == DBNull.Value)
+        {
+            return null;
+        }
+
+        return Convert.ToInt64(result);
+    }
+
+    public async Task<long> SaveAsync(InstrumentRecord record, CancellationToken cancellationToken)
+    {
+        if (record == null)
+        {
+            throw new ArgumentNullException(nameof(record));
+        }
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        if (record.Id <= 0)
+        {
+            const string insertSql = @"
+INSERT INTO dbo.Instruments
+(
+    RegistryNumber,
+    Name,
+    TypeDesignation,
+    Manufacturer,
+    VerificationInterval,
+    CertificateOrSerialNumber,
+    AllowsBatchVerification,
+    HasPeriodicVerification,
+    TypeInfo,
+    Purpose,
+    Description,
+    Software,
+    MetrologicalCharacteristics,
+    Completeness,
+    Verification,
+    RegulatoryDocuments,
+    Applicant,
+    TestCenter,
+    DetailUrl,
+    SourceSystem,
+    LastImportedAt,
+    CreatedAt,
+    UpdatedAt
+)
+OUTPUT INSERTED.Id
+VALUES
+(
+    @RegistryNumber,
+    @Name,
+    @TypeDesignation,
+    @Manufacturer,
+    @VerificationInterval,
+    @CertificateOrSerialNumber,
+    @AllowsBatchVerification,
+    @HasPeriodicVerification,
+    @TypeInfo,
+    @Purpose,
+    @Description,
+    @Software,
+    @MetrologicalCharacteristics,
+    @Completeness,
+    @Verification,
+    @RegulatoryDocuments,
+    @Applicant,
+    @TestCenter,
+    @DetailUrl,
+    @SourceSystem,
+    @LastImportedAt,
+    SYSUTCDATETIME(),
+    SYSUTCDATETIME()
+);";
+
+            await using var command = CreateRecordCommand(insertSql, connection, record);
+            var id = await command.ExecuteScalarAsync(cancellationToken);
+            return Convert.ToInt64(id);
+        }
+
+        const string updateSql = @"
+UPDATE dbo.Instruments
+SET
+    RegistryNumber = @RegistryNumber,
+    Name = @Name,
+    TypeDesignation = @TypeDesignation,
+    Manufacturer = @Manufacturer,
+    VerificationInterval = @VerificationInterval,
+    CertificateOrSerialNumber = @CertificateOrSerialNumber,
+    AllowsBatchVerification = @AllowsBatchVerification,
+    HasPeriodicVerification = @HasPeriodicVerification,
+    TypeInfo = @TypeInfo,
+    Purpose = @Purpose,
+    Description = @Description,
+    Software = @Software,
+    MetrologicalCharacteristics = @MetrologicalCharacteristics,
+    Completeness = @Completeness,
+    Verification = @Verification,
+    RegulatoryDocuments = @RegulatoryDocuments,
+    Applicant = @Applicant,
+    TestCenter = @TestCenter,
+    DetailUrl = @DetailUrl,
+    SourceSystem = @SourceSystem,
+    LastImportedAt = @LastImportedAt,
+    UpdatedAt = SYSUTCDATETIME()
+WHERE Id = @Id;";
+
+        await using (var command = CreateRecordCommand(updateSql, connection, record))
+        {
+            command.Parameters.AddWithValue("@Id", record.Id);
+            await command.ExecuteNonQueryAsync(cancellationToken);
+        }
+
+        return record.Id;
+    }
+
+    public async Task<PdfAttachment> FindAttachmentBySourceUrlAsync(long instrumentId, string sourceUrl, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(sourceUrl))
+        {
+            return null;
+        }
+
+        const string sql = @"
+SELECT
+    Id,
+    InstrumentId,
+    Kind,
+    Title,
+    SourceUrl,
+    LocalPath,
+    IsManual,
+    CreatedAt
+FROM dbo.PdfAttachments
+WHERE InstrumentId = @InstrumentId
+  AND SourceUrl = @SourceUrl;";
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        await using var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+        command.Parameters.AddWithValue("@InstrumentId", instrumentId);
+        command.Parameters.AddWithValue("@SourceUrl", sourceUrl);
+
+        await using var reader = await command.ExecuteReaderAsync(cancellationToken);
+        if (!await reader.ReadAsync(cancellationToken))
+        {
+            return null;
+        }
+
+        return new PdfAttachment
+        {
+            Id = reader.GetInt64(0),
+            InstrumentId = reader.GetInt64(1),
+            Kind = GetString(reader, 2),
+            Title = GetString(reader, 3),
+            SourceUrl = GetString(reader, 4),
+            LocalPath = GetString(reader, 5),
+            IsManual = reader.GetBoolean(6),
+            CreatedAt = reader.GetDateTime(7)
+        };
+    }
+
+    public async Task SaveAttachmentAsync(PdfAttachment attachment, CancellationToken cancellationToken)
+    {
+        if (attachment == null)
+        {
+            throw new ArgumentNullException(nameof(attachment));
+        }
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        if (attachment.Id <= 0)
+        {
+            const string insertSql = @"
+INSERT INTO dbo.PdfAttachments
+(
+    InstrumentId,
+    Kind,
+    Title,
+    SourceUrl,
+    LocalPath,
+    IsManual,
+    CreatedAt
+)
+VALUES
+(
+    @InstrumentId,
+    @Kind,
+    @Title,
+    @SourceUrl,
+    @LocalPath,
+    @IsManual,
+    SYSUTCDATETIME()
+);";
+
+            await using var command = CreateAttachmentCommand(insertSql, connection, attachment);
+            await command.ExecuteNonQueryAsync(cancellationToken);
+            return;
+        }
+
+        const string updateSql = @"
+UPDATE dbo.PdfAttachments
+SET
+    Kind = @Kind,
+    Title = @Title,
+    SourceUrl = @SourceUrl,
+    LocalPath = @LocalPath,
+    IsManual = @IsManual
+WHERE Id = @Id;";
+
+        await using (var command = CreateAttachmentCommand(updateSql, connection, attachment))
+        {
+            command.Parameters.AddWithValue("@Id", attachment.Id);
+            await command.ExecuteNonQueryAsync(cancellationToken);
+        }
+    }
+
+    public async Task DeleteAttachmentAsync(long attachmentId, CancellationToken cancellationToken)
+    {
+        const string sql = "DELETE FROM dbo.PdfAttachments WHERE Id = @Id;";
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        await using var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+        command.Parameters.AddWithValue("@Id", attachmentId);
+        await command.ExecuteNonQueryAsync(cancellationToken);
+    }
+
+    public async Task DeleteInstrumentAsync(long id, CancellationToken cancellationToken)
+    {
+        const string sql = "DELETE FROM dbo.Instruments WHERE Id = @Id;";
+
+        await using var connection = _connectionFactory.CreateConnection();
+        await connection.OpenAsync(cancellationToken);
+
+        await using var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+        command.Parameters.AddWithValue("@Id", id);
+        await command.ExecuteNonQueryAsync(cancellationToken);
+    }
+
+    private async Task<IReadOnlyList<PdfAttachment>> GetAttachmentsAsync(SqlConnection connection, long instrumentId, CancellationToken cancellationToken)
+    {
+        const string sql = @"
+SELECT
+    Id,
+    InstrumentId,
+    Kind,
+    Title,
+    SourceUrl,
+    LocalPath,
+    IsManual,
+    CreatedAt
+FROM dbo.PdfAttachments
+WHERE InstrumentId = @InstrumentId
+ORDER BY CreatedAt DESC, Id DESC;";
+
+        var items = new List<PdfAttachment>();
+
+        await using var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+        command.Parameters.AddWithValue("@InstrumentId", instrumentId);
+
+        await using var reader = await command.ExecuteReaderAsync(cancellationToken);
+        while (await reader.ReadAsync(cancellationToken))
+        {
+            items.Add(new PdfAttachment
+            {
+                Id = reader.GetInt64(0),
+                InstrumentId = reader.GetInt64(1),
+                Kind = GetString(reader, 2),
+                Title = GetString(reader, 3),
+                SourceUrl = GetString(reader, 4),
+                LocalPath = GetString(reader, 5),
+                IsManual = reader.GetBoolean(6),
+                CreatedAt = reader.GetDateTime(7)
+            });
+        }
+
+        return items;
+    }
+
+    private SqlCommand CreateRecordCommand(string sql, SqlConnection connection, InstrumentRecord record)
+    {
+        var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+
+        command.Parameters.AddWithValue("@RegistryNumber", ToDbValue(record.RegistryNumber));
+        command.Parameters.AddWithValue("@Name", string.IsNullOrWhiteSpace(record.Name) ? "Без названия" : record.Name.Trim());
+        command.Parameters.AddWithValue("@TypeDesignation", ToDbValue(record.TypeDesignation));
+        command.Parameters.AddWithValue("@Manufacturer", ToDbValue(record.Manufacturer));
+        command.Parameters.AddWithValue("@VerificationInterval", ToDbValue(record.VerificationInterval));
+        command.Parameters.AddWithValue("@CertificateOrSerialNumber", ToDbValue(record.CertificateOrSerialNumber));
+        command.Parameters.AddWithValue("@AllowsBatchVerification", ToDbValue(record.AllowsBatchVerification));
+        command.Parameters.AddWithValue("@HasPeriodicVerification", ToDbValue(record.HasPeriodicVerification));
+        command.Parameters.AddWithValue("@TypeInfo", ToDbValue(record.TypeInfo));
+        command.Parameters.AddWithValue("@Purpose", ToDbValue(record.Purpose));
+        command.Parameters.AddWithValue("@Description", ToDbValue(record.Description));
+        command.Parameters.AddWithValue("@Software", ToDbValue(record.Software));
+        command.Parameters.AddWithValue("@MetrologicalCharacteristics", ToDbValue(record.MetrologicalCharacteristics));
+        command.Parameters.AddWithValue("@Completeness", ToDbValue(record.Completeness));
+        command.Parameters.AddWithValue("@Verification", ToDbValue(record.Verification));
+        command.Parameters.AddWithValue("@RegulatoryDocuments", ToDbValue(record.RegulatoryDocuments));
+        command.Parameters.AddWithValue("@Applicant", ToDbValue(record.Applicant));
+        command.Parameters.AddWithValue("@TestCenter", ToDbValue(record.TestCenter));
+        command.Parameters.AddWithValue("@DetailUrl", ToDbValue(record.DetailUrl));
+        command.Parameters.AddWithValue("@SourceSystem", string.IsNullOrWhiteSpace(record.SourceSystem) ? "Manual" : record.SourceSystem.Trim());
+        command.Parameters.AddWithValue("@LastImportedAt", record.LastImportedAt.HasValue ? record.LastImportedAt.Value : DBNull.Value);
+
+        return command;
+    }
+
+    private SqlCommand CreateAttachmentCommand(string sql, SqlConnection connection, PdfAttachment attachment)
+    {
+        var command = new SqlCommand(sql, connection)
+        {
+            CommandTimeout = _connectionFactory.Options.CommandTimeoutSeconds
+        };
+
+        command.Parameters.AddWithValue("@InstrumentId", attachment.InstrumentId);
+        command.Parameters.AddWithValue("@Kind", string.IsNullOrWhiteSpace(attachment.Kind) ? "PDF" : attachment.Kind.Trim());
+        command.Parameters.AddWithValue("@Title", ToDbValue(attachment.Title));
+        command.Parameters.AddWithValue("@SourceUrl", ToDbValue(attachment.SourceUrl));
+        command.Parameters.AddWithValue("@LocalPath", ToDbValue(attachment.LocalPath));
+        command.Parameters.AddWithValue("@IsManual", attachment.IsManual);
+
+        return command;
+    }
+
+    private static object ToDbValue(string value)
+    {
+        return string.IsNullOrWhiteSpace(value) ? DBNull.Value : value.Trim();
+    }
+
+    private static string GetString(SqlDataReader reader, int index)
+    {
+        return reader.IsDBNull(index) ? null : reader.GetString(index);
+    }
+}
diff --git a/Services/KtoPoveritClient.cs b/Services/KtoPoveritClient.cs
new file mode 100644
index 0000000..17f7230
--- /dev/null
+++ b/Services/KtoPoveritClient.cs
@@ -0,0 +1,187 @@
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using CRAWLER.Configuration;
+using Microsoft.Extensions.Configuration;
+
+namespace CRAWLER.Services;
+
+internal sealed class KtoPoveritClient : IDisposable
+{
+    private readonly CrawlerOptions _options;
+    private readonly HttpClient _httpClient;
+
+    public KtoPoveritClient(IConfiguration configuration)
+    {
+        _options = configuration.GetSection("Crawler").Get<CrawlerOptions>()
+                   ?? throw new InvalidOperationException("Раздел Crawler не найден в appsettings.json.");
+
+        var handler = new SocketsHttpHandler
+        {
+            AutomaticDecompression = DecompressionMethods.All,
+            AllowAutoRedirect = false
+        };
+
+        _httpClient = new HttpClient(handler)
+        {
+            Timeout = TimeSpan.FromSeconds(Math.Max(5, _options.TimeoutSeconds))
+        };
+        _httpClient.DefaultRequestHeaders.UserAgent.ParseAdd(_options.UserAgent);
+        _httpClient.DefaultRequestHeaders.AcceptLanguage.ParseAdd("ru-RU,ru;q=0.9,en-US;q=0.8");
+    }
+
+    public CrawlerOptions Options
+    {
+        get { return _options; }
+    }
+
+    public async Task<string> GetStringAsync(string url, CancellationToken cancellationToken)
+    {
+        using var request = CreateRequest(url);
+        using var response = await SendAsync(request, cancellationToken);
+        return await response.Content.ReadAsStringAsync(cancellationToken);
+    }
+
+    public async Task<byte[]> GetBytesAsync(string url, CancellationToken cancellationToken)
+    {
+        using var request = CreateRequest(url);
+        using var response = await SendAsync(request, cancellationToken);
+        return await response.Content.ReadAsByteArrayAsync(cancellationToken);
+    }
+
+    public string BuildCatalogPageUrl(int page)
+    {
+        var relative = string.Format(_options.CatalogPathFormat, page);
+        return BuildAbsoluteUrl(relative);
+    }
+
+    public string BuildAbsoluteUrl(string urlOrPath)
+    {
+        if (string.IsNullOrWhiteSpace(urlOrPath))
+        {
+            return null;
+        }
+
+        if (Uri.TryCreate(urlOrPath, UriKind.Absolute, out var absoluteUri))
+        {
+            return absoluteUri.ToString();
+        }
+
+        var baseUri = new Uri(_options.BaseUrl.TrimEnd('/') + "/");
+        return new Uri(baseUri, urlOrPath.TrimStart('/')).ToString();
+    }
+
+    private HttpRequestMessage CreateRequest(string url)
+    {
+        return new HttpRequestMessage(HttpMethod.Get, url)
+        {
+            Version = HttpVersion.Version11,
+            VersionPolicy = HttpVersionPolicy.RequestVersionOrLower
+        };
+    }
+
+    private async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+    {
+        var currentUri = request.RequestUri ?? throw new InvalidOperationException("Не задан URL запроса.");
+        const int maxRedirects = 10;
+
+        try
+        {
+            for (var redirectIndex = 0; redirectIndex <= maxRedirects; redirectIndex++)
+            {
+                using var currentRequest = CreateRequest(currentUri.ToString());
+                var response = await _httpClient.SendAsync(currentRequest, HttpCompletionOption.ResponseContentRead, cancellationToken);
+
+                if (IsRedirectStatusCode(response.StatusCode))
+                {
+                    var redirectUri = ResolveRedirectUri(currentUri, response.Headers);
+                    response.Dispose();
+
+                    if (redirectUri == null)
+                    {
+                        throw new InvalidOperationException(
+                            $"Сайт вернул {(int)response.StatusCode} для {currentUri}, но не прислал корректный адрес перенаправления.");
+                    }
+
+                    currentUri = redirectUri;
+                    continue;
+                }
+
+                if ((int)response.StatusCode >= 200 && (int)response.StatusCode <= 299)
+                {
+                    return response;
+                }
+
+                var statusCode = (int)response.StatusCode;
+                var reasonPhrase = response.ReasonPhrase;
+                response.Dispose();
+                throw new HttpRequestException(
+                    $"Response status code does not indicate success: {statusCode} ({reasonPhrase}).");
+            }
+
+            throw new InvalidOperationException(
+                $"Превышено число перенаправлений ({maxRedirects}) для {currentUri}.");
+        }
+        catch (Exception ex)
+        {
+            throw new InvalidOperationException(
+                $"Не удалось получить данные с сайта Кто поверит: {request.RequestUri}. {ex.Message}",
+                ex);
+        }
+    }
+
+    private static bool IsRedirectStatusCode(HttpStatusCode statusCode)
+    {
+        return statusCode == HttpStatusCode.Moved
+               || statusCode == HttpStatusCode.Redirect
+               || statusCode == HttpStatusCode.RedirectMethod
+               || statusCode == HttpStatusCode.TemporaryRedirect
+               || (int)statusCode == 308;
+    }
+
+    private static Uri ResolveRedirectUri(Uri currentUri, HttpResponseHeaders headers)
+    {
+        if (headers.Location != null)
+        {
+            return headers.Location.IsAbsoluteUri
+                ? headers.Location
+                : new Uri(currentUri, headers.Location);
+        }
+
+        if (!headers.TryGetValues("Location", out var values))
+        {
+            return null;
+        }
+
+        var rawLocation = values.FirstOrDefault();
+        if (string.IsNullOrWhiteSpace(rawLocation))
+        {
+            return null;
+        }
+
+        if (Uri.TryCreate(rawLocation, UriKind.Absolute, out var absoluteUri))
+        {
+            return absoluteUri;
+        }
+
+        if (Uri.TryCreate(currentUri, rawLocation, out var relativeUri))
+        {
+            return relativeUri;
+        }
+
+        var escaped = Uri.EscapeUriString(rawLocation);
+        if (Uri.TryCreate(escaped, UriKind.Absolute, out absoluteUri))
+        {
+            return absoluteUri;
+        }
+
+        return Uri.TryCreate(currentUri, escaped, out relativeUri)
+            ? relativeUri
+            : null;
+    }
+
+    public void Dispose()
+    {
+        _httpClient.Dispose();
+    }
+}
diff --git a/Services/PdfShellService.cs b/Services/PdfShellService.cs
new file mode 100644
index 0000000..317e4fd
--- /dev/null
+++ b/Services/PdfShellService.cs
@@ -0,0 +1,46 @@
+using System.Diagnostics;
+using System.IO;
+using CRAWLER.Models;
+
+namespace CRAWLER.Services;
+
+internal interface IPdfOpener
+{
+    void OpenAttachment(PdfAttachment attachment);
+    void OpenUri(string uri);
+}
+
+internal sealed class PdfShellService : IPdfOpener
+{
+    public void OpenAttachment(PdfAttachment attachment)
+    {
+        if (attachment == null)
+        {
+            return;
+        }
+
+        if (!string.IsNullOrWhiteSpace(attachment.LocalPath) && File.Exists(attachment.LocalPath))
+        {
+            OpenUri(attachment.LocalPath);
+            return;
+        }
+
+        if (!string.IsNullOrWhiteSpace(attachment.SourceUrl))
+        {
+            OpenUri(attachment.SourceUrl);
+        }
+    }
+
+    public void OpenUri(string uri)
+    {
+        if (string.IsNullOrWhiteSpace(uri))
+        {
+            return;
+        }
+
+        Process.Start(new ProcessStartInfo(uri)
+        {
+            UseShellExecute = true
+        });
+    }
+}
diff --git a/Services/PdfStorageService.cs b/Services/PdfStorageService.cs
new file mode 100644
index 0000000..df558cd
--- /dev/null
+++ b/Services/PdfStorageService.cs
@@ -0,0 +1,91 @@
+using System.IO;
+using System.Linq;
+using CRAWLER.Configuration;
+using Microsoft.Extensions.Configuration;
+
+namespace CRAWLER.Services;
+
+internal sealed class PdfStorageService
+{
+    private readonly KtoPoveritClient _client;
+    private readonly string _rootPath;
+
+    public PdfStorageService(IConfiguration configuration, KtoPoveritClient client)
+    {
+        _client = client;
+        var options = configuration.GetSection("Crawler").Get<CrawlerOptions>()
+                      ?? throw new InvalidOperationException("Раздел Crawler не найден в appsettings.json.");
+        _rootPath = Environment.ExpandEnvironmentVariables(options.PdfStoragePath);
+        Directory.CreateDirectory(_rootPath);
+    }
+
+    public async Task<string> DownloadAsync(string sourceUrl, string registryNumber, string title, CancellationToken cancellationToken)
+    {
+        var bytes = await _client.GetBytesAsync(sourceUrl, cancellationToken);
+        var fullPath = BuildTargetPath(registryNumber, title, sourceUrl);
+        await File.WriteAllBytesAsync(fullPath, bytes, cancellationToken);
+        return fullPath;
+    }
+
+    public async Task<string> CopyFromLocalAsync(string sourcePath, string registryNumber, string title, CancellationToken cancellationToken)
+    {
+        var fullPath = BuildTargetPath(registryNumber, title, sourcePath);
+
+        await using var sourceStream = File.Open(sourcePath, FileMode.Open, FileAccess.Read, FileShare.Read);
+        await using var targetStream = File.Create(fullPath);
+        await sourceStream.CopyToAsync(targetStream, cancellationToken);
+        return fullPath;
+    }
+
+    public void TryDelete(string path)
+    {
+        try
+        {
+            if (!string.IsNullOrWhiteSpace(path) && File.Exists(path))
+            {
+                File.Delete(path);
+            }
+        }
+        catch
+        {
+        }
+    }
+
+    private string BuildTargetPath(string registryNumber, string title, string sourceIdentity)
+    {
+        var safeFolder = MakeSafePathSegment(string.IsNullOrWhiteSpace(registryNumber) ? "manual" : registryNumber);
+        var folder = Path.Combine(_rootPath, safeFolder);
+        Directory.CreateDirectory(folder);
+
+        var baseName = MakeSafePathSegment(string.IsNullOrWhiteSpace(title) ? Path.GetFileNameWithoutExtension(sourceIdentity) : title);
+        if (string.IsNullOrWhiteSpace(baseName))
+        {
+            baseName = "document";
+        }
+
+        var fullPath = Path.Combine(folder, baseName + ".pdf");
+        if (!File.Exists(fullPath))
+        {
+            return fullPath;
+        }
+
+        var counter = 2;
+        while (true)
+        {
+            var candidate = Path.Combine(folder, $"{baseName}-{counter}.pdf");
+            if (!File.Exists(candidate))
+            {
+                return candidate;
+            }
+
+            counter++;
+        }
+    }
+
+    private static string MakeSafePathSegment(string value)
+    {
+        var invalid = Path.GetInvalidFileNameChars();
+        var cleaned = new string((value ?? string.Empty).Select(ch => invalid.Contains(ch) ? '_' : ch).ToArray()).Trim();
+        return string.IsNullOrWhiteSpace(cleaned) ? "file" : cleaned;
+    }
+}
diff --git a/Services/SqlServerConnectionFactory.cs b/Services/SqlServerConnectionFactory.cs
new file mode 100644
index 0000000..57b9579
--- /dev/null
+++ b/Services/SqlServerConnectionFactory.cs
@@ -0,0 +1,55 @@
+using CRAWLER.Configuration;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Configuration;
+
+namespace CRAWLER.Services;
+
+internal interface IDatabaseConnectionFactory
+{
+    SqlConnection CreateConnection();
+    SqlConnection CreateMasterConnection();
+    DatabaseOptions Options { get; }
+}
+
+internal sealed class SqlServerConnectionFactory : IDatabaseConnectionFactory
+{
+    public SqlServerConnectionFactory(IConfiguration configuration)
+    {
+        Options = configuration.GetSection("Database").Get<DatabaseOptions>()
+                  ?? throw new InvalidOperationException("Раздел Database не найден в appsettings.json.");
+    }
+
+    public DatabaseOptions Options { get; }
+
+    public SqlConnection CreateConnection()
+    {
+        return new SqlConnection(BuildConnectionString(Options.Database));
+    }
+
+    public SqlConnection CreateMasterConnection()
+    {
+        return new SqlConnection(BuildConnectionString("master"));
+    }
+
+    private string BuildConnectionString(string databaseName)
+    {
+        var builder = new SqlConnectionStringBuilder
+        {
+            ApplicationName = Options.ApplicationName,
+            DataSource = Options.Server,
+            InitialCatalog = databaseName,
+            ConnectTimeout = Options.ConnectTimeoutSeconds,
+            Encrypt = Options.Encrypt,
+            IntegratedSecurity = Options.IntegratedSecurity,
+            MultipleActiveResultSets = Options.MultipleActiveResultSets,
+            Pooling = Options.Pooling,
+            MaxPoolSize = Options.MaxPoolSize,
+            MinPoolSize = Options.MinPoolSize,
+            TrustServerCertificate = Options.TrustServerCertificate,
+            ConnectRetryCount = Options.ConnectRetryCount,
+            ConnectRetryInterval = Options.ConnectRetryIntervalSeconds
+        };
+
+        return builder.ConnectionString;
+    }
+}
diff --git a/ViewModels/EditInstrumentWindowViewModel.cs b/ViewModels/EditInstrumentWindowViewModel.cs
new file mode 100644
index 0000000..9cdeeac
--- /dev/null
+++ b/ViewModels/EditInstrumentWindowViewModel.cs
@@ -0,0 +1,79 @@
+using System.Collections.ObjectModel;
+using System.Linq;
+using CRAWLER.Infrastructure;
+using CRAWLER.Models;
+
+namespace CRAWLER.ViewModels;
+
+internal sealed class EditInstrumentWindowViewModel : ObservableObject
+{
+    private readonly InstrumentRecord _draft;
+    private PendingPdfFile _selectedPendingPdf;
+
+    public EditInstrumentWindowViewModel(InstrumentRecord draft, bool isNewRecord)
+    {
+        _draft = draft ?? new InstrumentRecord();
+        PendingPdfFiles = new ObservableCollection<PendingPdfFile>();
+        ExistingAttachments = new ObservableCollection<PdfAttachment>(_draft.Attachments ?? Enumerable.Empty<PdfAttachment>());
+        WindowTitle = isNewRecord ? "Новая запись" : $"Редактирование: {(_draft.RegistryNumber ?? _draft.Name)}";
+    }
+
+    public string WindowTitle { get; }
+
+    public ObservableCollection<PendingPdfFile> PendingPdfFiles { get; }
+
+    public ObservableCollection<PdfAttachment> ExistingAttachments { get; }
+
+    public PendingPdfFile SelectedPendingPdf
+    {
+        get { return _selectedPendingPdf; }
+        set { SetProperty(ref _selectedPendingPdf, value); }
+    }
+
+    public InstrumentRecord Draft
+    {
+        get { return _draft; }
+    }
+
+    public void AddPendingFiles(IReadOnlyList<string> paths)
+    {
+        foreach (var path in paths.Where(path => !string.IsNullOrWhiteSpace(path)))
+        {
+            if (PendingPdfFiles.Any(item => string.Equals(item.SourcePath, path, StringComparison.OrdinalIgnoreCase)))
+            {
+                continue;
+            }
+
+            PendingPdfFiles.Add(new PendingPdfFile
+            {
+                SourcePath = path,
+                DisplayName = System.IO.Path.GetFileName(path)
+            });
+        }
+    }
+
+    public void RemovePendingSelected()
+    {
+        if (SelectedPendingPdf != null)
+        {
+            PendingPdfFiles.Remove(SelectedPendingPdf);
+        }
+    }
+
+    public string[] GetPendingPaths()
+    {
+        return PendingPdfFiles.Select(item => item.SourcePath).ToArray();
+    }
+
+    public bool Validate(out string errorMessage)
+    {
+        if (string.IsNullOrWhiteSpace(Draft.Name))
+        {
+            errorMessage = "Укажите наименование средства измерения.";
+            return false;
+        }
+
+        errorMessage = null;
+        return true;
+    }
+}
diff --git a/ViewModels/MainWindowViewModel.cs b/ViewModels/MainWindowViewModel.cs
new file mode 100644
index 0000000..41dcf5d
--- /dev/null
+++ b/ViewModels/MainWindowViewModel.cs
@@ -0,0 +1,266 @@
+using System;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using CRAWLER.Infrastructure;
+using CRAWLER.Models;
+using CRAWLER.Services;
+
+namespace CRAWLER.ViewModels;
+
+internal sealed class MainWindowViewModel : ObservableObject
+{
+    private readonly InstrumentCatalogService _catalogService;
+    private readonly IPdfOpener _pdfOpener;
+    private InstrumentSummary _selectedSummary;
+    private InstrumentRecord _selectedInstrument;
+    private string _searchText;
+    private int _pagesToScan;
+    private string _statusText;
+    private bool _isBusy;
+    private CancellationTokenSource _selectionCancellationTokenSource;
+
+    public MainWindowViewModel(InstrumentCatalogService catalogService, IPdfOpener pdfOpener)
+    {
+        _catalogService = catalogService;
+        _pdfOpener = pdfOpener;
+        _pagesToScan = _catalogService.DefaultPagesToScan;
+        _statusText = "Готово.";
+        Instruments = new ObservableCollection<InstrumentSummary>();
+    }
+
+    public ObservableCollection<InstrumentSummary> Instruments { get; }
+
+    public InstrumentSummary SelectedSummary
+    {
+        get { return _selectedSummary; }
+        set
+        {
+            if (SetProperty(ref _selectedSummary, value))
+            {
+                _ = LoadSelectedInstrumentAsync(value?.Id);
+            }
+        }
+    }
+
+    public InstrumentRecord SelectedInstrument
+    {
+        get { return _selectedInstrument; }
+        private set { SetProperty(ref _selectedInstrument, value); }
+    }
+
+    public string SearchText
+    {
+        get { return _searchText; }
+        set { SetProperty(ref _searchText, value); }
+    }
+
+    public int PagesToScan
+    {
+        get { return _pagesToScan; }
+        set { SetProperty(ref _pagesToScan, value < 1 ? 1 : value); }
+    }
+
+    public string StatusText
+    {
+        get { return _statusText; }
+        private set { SetProperty(ref _statusText, value); }
+    }
+
+    public bool IsBusy
+    {
+        get { return _isBusy; }
+        private set { SetProperty(ref _isBusy, value); }
+    }
+
+    public async Task InitializeAsync()
+    {
+        await RunBusyAsync(async () =>
+        {
+            StatusText = "Подготовка базы данных...";
+            await _catalogService.InitializeAsync(CancellationToken.None);
+            await RefreshAsync();
+        });
+    }
+
+    public async Task RefreshAsync(long? selectId = null)
+    {
+        await RunBusyAsync(async () =>
+        {
+            StatusText = "Загрузка списка записей...";
+
+            var items = await _catalogService.SearchAsync(SearchText, CancellationToken.None);
+            Instruments.Clear();
+            foreach (var item in items)
+            {
+                Instruments.Add(item);
+            }
+
+            if (Instruments.Count == 0)
+            {
+                SelectedInstrument = null;
+                SelectedSummary = null;
+                StatusText = "Записи не найдены.";
+                return;
+            }
+
+            var summary = selectId.HasValue
+                ? Instruments.FirstOrDefault(item => item.Id == selectId.Value)
+                : SelectedSummary == null
+                    ? Instruments.FirstOrDefault()
+                    : Instruments.FirstOrDefault(item => item.Id == SelectedSummary.Id) ?? Instruments.FirstOrDefault();
+
+            SelectedSummary = summary;
+            StatusText = $"Загружено записей: {Instruments.Count}.";
+        });
+    }
+
+    public async Task<SyncResult> SyncAsync()
+    {
+        SyncResult result = null;
+
+        await RunBusyAsync(async () =>
+        {
+            var progress = new Progress<string>(message => StatusText = message);
+            result = await _catalogService.SyncFromSiteAsync(PagesToScan, progress, CancellationToken.None);
+            await RefreshAsync(SelectedSummary?.Id);
+        });
+
+        return result;
+    }
+
+    public InstrumentRecord CreateNewDraft()
+    {
+        return new InstrumentRecord
+        {
+            SourceSystem = "Manual"
+        };
+    }
+
+    public InstrumentRecord CreateDraftFromSelected()
+    {
+        return SelectedInstrument?.Clone();
+    }
+
+    public async Task<long> SaveAsync(InstrumentRecord draft, System.Collections.Generic.IEnumerable<string> pendingPdfPaths)
+    {
+        long id = 0;
+
+        await RunBusyAsync(async () =>
+        {
+            StatusText = "Сохранение записи...";
+            id = await _catalogService.SaveInstrumentAsync(draft, pendingPdfPaths, CancellationToken.None);
+            await RefreshAsync(id);
+            StatusText = "Изменения сохранены.";
+        });
+
+        return id;
+    }
+
+    public async Task DeleteSelectedAsync()
+    {
+        if (SelectedInstrument == null)
+        {
+            return;
+        }
+
+        var deletedId = SelectedInstrument.Id;
+
+        await RunBusyAsync(async () =>
+        {
+            StatusText = "Удаление записи...";
+            await _catalogService.DeleteInstrumentAsync(SelectedInstrument, CancellationToken.None);
+            await RefreshAsync();
+            StatusText = $"Запись {deletedId} удалена.";
+        });
+    }
+
+    public async Task AddAttachmentsToSelectedAsync(System.Collections.Generic.IEnumerable<string> paths)
+    {
+        if (SelectedInstrument == null)
+        {
+            return;
+        }
+
+        await RunBusyAsync(async () =>
+        {
+            StatusText = "Копирование PDF-файлов...";
+            await _catalogService.AddManualAttachmentsAsync(SelectedInstrument.Id, SelectedInstrument.RegistryNumber, paths, CancellationToken.None);
+            await LoadSelectedInstrumentAsync(SelectedInstrument.Id);
+            StatusText = "PDF-файлы добавлены.";
+        });
+    }
+
+    public async Task RemoveAttachmentAsync(PdfAttachment attachment)
+    {
+        if (attachment == null || SelectedInstrument == null)
+        {
+            return;
+        }
+
+        await RunBusyAsync(async () =>
+        {
+            StatusText = "Удаление PDF-файла...";
+            await _catalogService.RemoveAttachmentAsync(attachment, CancellationToken.None);
+            await LoadSelectedInstrumentAsync(SelectedInstrument.Id);
+            StatusText = "PDF-файл удалён.";
+        });
+    }
+
+    public void OpenAttachment(PdfAttachment attachment)
+    {
+        _pdfOpener.OpenAttachment(attachment);
+    }
+
+    public void OpenSourceUrl()
+    {
+        if (SelectedInstrument != null && !string.IsNullOrWhiteSpace(SelectedInstrument.DetailUrl))
+        {
+            _pdfOpener.OpenUri(SelectedInstrument.DetailUrl);
+        }
+    }
+
+    private async Task LoadSelectedInstrumentAsync(long? id)
+    {
+        _selectionCancellationTokenSource?.Cancel();
+        _selectionCancellationTokenSource = new CancellationTokenSource();
+        var token = _selectionCancellationTokenSource.Token;
+
+        if (!id.HasValue)
+        {
+            SelectedInstrument = null;
+            return;
+        }
+
+        try
+        {
+            var instrument = await _catalogService.GetByIdAsync(id.Value, token);
+            if (!token.IsCancellationRequested)
+            {
+                SelectedInstrument = instrument;
+            }
+        }
+        catch (OperationCanceledException)
+        {
+        }
+    }
+
+    private async Task RunBusyAsync(Func<Task> action)
+    {
+        if (IsBusy)
+        {
+            return;
+        }
+
+        try
+        {
+            IsBusy = true;
+            await action();
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+}
diff --git a/appsettings.json b/appsettings.json
new file mode 100644
index 0000000..7485248
--- /dev/null
+++ b/appsettings.json
@@ -0,0 +1,27 @@
+{
+  "Database": {
+    "ApplicationName": "CRAWLER",
+    "CommandTimeoutSeconds": 60,
+    "ConnectRetryCount": 3,
+    "ConnectRetryIntervalSeconds": 5,
+    "ConnectTimeoutSeconds": 15,
+    "Database": "CRAWLER",
+    "Encrypt": false,
+    "IntegratedSecurity": true,
+    "MultipleActiveResultSets": true,
+    "Pooling": true,
+    "MaxPoolSize": 100,
+    "MinPoolSize": 0,
+    "Server": "SEVENHILL\\SQLEXPRESS",
+    "TrustServerCertificate": true
+  },
+  "Crawler": {
+    "BaseUrl": "https://www.ktopoverit.ru",
+    "CatalogPathFormat": "/poverka/gosreestr_sredstv_izmereniy?page={0}",
+    "RequestDelayMilliseconds": 350,
+    "DefaultPagesToScan": 1,
+    "PdfStoragePath": "%LOCALAPPDATA%\\CRAWLER\\PdfStore",
+    "TimeoutSeconds": 30,
+    "UserAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) CRAWLER/1.0"
+  }
+}