fix: correct /stats wiki page count and Wiki.js listing pagination

- /stats passed the bare user name as path prefix (matched nothing, always
  reported 0 of 138 pages); it now counts pages under users/{user}
- list_pages applied the API-side limit before client-side path/tag filters,
  dropping matching pages that sort late; limit now applies after filtering
- list_all_pages replaced the fake while/break pagination with a real
  limit-growth loop: Wiki.js 2.x pages.list supports only a limit argument
  (no offset - verified via GraphQL introspection), so the client doubles
  the limit until the API returns fewer pages than requested

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/main.py

@@ -192,10 +192,10 @@ async def stats(
         logger.error(f"Failed to get Qdrant stats: {e}")
         qdrant_stats = {"error": str(e)}
 
-    # Wiki.js page count
+    # Wiki.js page count (pages live under the user namespace, e.g. "users/jpmschweitzer/...")
     wiki_pages = 0
     try:
-        pages = await wikijs.list_all_pages(user)
+        pages = await wikijs.list_all_pages(path_prefix=f"users/{user}")
         wiki_pages = len(pages)
     except Exception as e:
         logger.warning(f"Failed to get Wiki.js stats: {e}")