fix(library-desk): ensure page_id is int in get_page GraphQL call

GraphQL requires Int type, but page_id might be passed as string.
Explicit int() conversion prevents 400 Bad Request errors.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

services/library-desk/src/clients/wikijs_client.py

@@ -351,7 +351,8 @@ class WikiJSClient:
         """
 
         try:
-            data = await self._execute_query(query, {"id": page_id})
+            # Ensure page_id is int (GraphQL requires Int, not String)
+            data = await self._execute_query(query, {"id": int(page_id)})
             page = data.get("pages", {}).get("single")
 
             # Extract tag strings from tag objects