feat: enhance performance logging and caching in various components

- Introduced slow callback logging in FastAPI to identify blocking calls.
- Added performance logging for agent creation and tool loading processes.
- Implemented caching for MCP tools to reduce redundant server calls.
- Enhanced sandbox management with in-process caching for improved efficiency.
- Refactored several functions for better readability and performance tracking.
- Updated tests to ensure proper functionality of new features and optimizations.

surfsense_backend/app/indexing_pipeline/connector_document.py

@@ -5,6 +5,7 @@ from app.db import DocumentType
 
 class ConnectorDocument(BaseModel):
     """Canonical data transfer object produced by connector adapters and consumed by the indexing pipeline."""
+
     title: str
     source_markdown: str
     unique_id: str