Initial QSfera import

Server/vendor/github.com/samber/slog-common/context.go

@@ -0,0 +1,24 @@
+package slogcommon
+
+import (
+	"context"
+	"log/slog"
+)
+
+func ContextExtractor(ctx context.Context, fns []func(ctx context.Context) []slog.Attr) []slog.Attr {
+	attrs := []slog.Attr{}
+	for _, fn := range fns {
+		attrs = append(attrs, fn(ctx)...)
+	}
+	return attrs
+}
+
+func ExtractFromContext(keys ...any) func(ctx context.Context) []slog.Attr {
+	return func(ctx context.Context) []slog.Attr {
+		attrs := make([]slog.Attr, 0, len(keys))
+		for _, key := range keys {
+			attrs = append(attrs, slog.Any(key.(string), ctx.Value(key)))
+		}
+		return attrs
+	}
+}