chore(F.15): FastMCP 3.x upgrade + legacy cleanup — v3.5.0

- Upgrade fastmcp from >=2.14.0,<3.0.0 to >=3.0.0,<4.0.0
- Remove server_multi.py (legacy multi-endpoint server)
- Remove core/project_manager.py (legacy project manager)
- Refactor HealthMonitor to use SiteManager exclusively
- Replace _tool_manager._tools with tracked _tool_counts dict
- Clean core/__init__.py exports
- Update CHANGELOG, CLAUDE.md, tests
- Auto-format fixes (black + ruff)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

plugins/supabase/handlers/auth.py

@@ -483,8 +483,6 @@ async def delete_user_factor(client: SupabaseClient, user_id: str, factor_id: st
         return json.dumps({"success": False, "error": str(e)}, indent=2, ensure_ascii=False)
 
 
-
-
 async def search_users(
     client: SupabaseClient, query: str, page: int = 1, per_page: int = 50
 ) -> str: