Fix viewer: safe JSON embed so search cards render again.

Co-authored-by: Cursor <cursoragent@cursor.com>

webapp/main.py

@@ -216,12 +216,14 @@ def viewer(
     home: Optional[str] = Query(None),
 ):
     sections = fetch_sections(prefix)
+    # Escape < so </script> inside text_html cannot break the page script tag
+    sections_json = json.dumps(sections, ensure_ascii=False, default=str).replace("<", "\\u003c")
     home_url = "/home-image" if (home or HOME_IMAGE or (BASE_DIR.parent / "Bairaci.png").exists()) else None
     return templates.TemplateResponse(
         request,
         "viewer.html",
         {
-            "sections_json": json.dumps(sections, ensure_ascii=False, default=str),
+            "sections_json": sections_json,
             "section_count": len(sections),
             "prefix": prefix or "",
             "home_url": home_url,