Relocate three leaf filesystem-cluster modules to the shared kernel and flip
all 38 importers. No re-export shims needed (no frozen single-agent importer).
This also resolves the pre-existing shared->new_chat back-edge from
shared/receipt_command.py onto filesystem_state.
filesystem_backends is intentionally deferred to slice 5: it depends on
new_chat middleware (kb_postgres_backend, multi_root_local_folder_backend)
that have not yet moved, so relocating it now would create a shared->new_chat edge.
- 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.
- Added functionality to persist sandbox files locally before deletion.
- Introduced methods for retrieving and deleting locally stored sandbox files.
- Updated routes to handle local file downloads and background deletion of sandboxes.
- Enhanced streaming tasks to support sandbox file management.
- Added _TimeoutAwareSandbox class to handle per-command timeouts in DaytonaSandbox.
- Updated _find_or_create function to manage sandbox states and restart stopped/archived sandboxes.
- Enhanced get_or_create_sandbox to return the new sandbox class.
- Introduced file download functionality in the frontend, allowing users to download generated files from the sandbox.
- Updated system prompt to include guidelines for sharing generated files.
