feat: add matched_path field to tree search results for consistency with advanced search response format

backend/main.py

@@ -1636,6 +1636,7 @@ async def api_tree_search(
                     "path": entry["path"],
                     "name": entry["name"],
                     "type": entry["type"],
+                    "matched_path": entry["path"],
                 })
 
     return {"query": q, "vault_filter": vault, "results": results}