Preserve QPowerPoint paragraph breaks on import

src/io/powerPointOffice.ts

@@ -178,7 +178,7 @@ function extractSlideTextBlocks(slideXml: unknown): SlideTextBlock[] {
   const textBodies = recordsByKey(slideXml, "txBody");
   const blocks = textBodies
     .map((textBody) => {
-      const text = normalizeWhitespace(extractTextBlocks(textBody).join("\n"));
+      const text = extractTextBodyText(textBody);
       if (!text) {
         return null;
       }
@@ -199,6 +199,14 @@ function extractSlideTextBlocks(slideXml: unknown): SlideTextBlock[] {
   return blocks.length > 0 ? blocks : extractTextBlocks(slideXml).map((text) => ({ text }));
 }
 
+function extractTextBodyText(textBody: Record<string, unknown>) {
+  const paragraphs = toArray(textBody.p)
+    .map((paragraph) => normalizeWhitespace(extractTextBlocks(paragraph).join("")))
+    .filter(Boolean);
+
+  return paragraphs.length > 0 ? paragraphs.join("\n") : normalizeWhitespace(extractTextBlocks(textBody).join("\n"));
+}
+
 export function listSlidePaths(
   zip: ZipArchive,
   presentationXml?: unknown,