shutil.move() in _load() can fail due to permissions, disk full, or
concurrent access. Without error handling, the exception propagates up
and prevents the session from loading entirely.
Wrap in try/except so migration failures are logged as warnings and the
session falls back to loading from the legacy path on next attempt.
Fixes#863
_handle_message() in _on_socket_request() had no try/except. If it
throws (bus full, permission error, etc.), the exception propagates up
and crashes the Socket Mode event loop, causing missed messages.
Other channels like Telegram already have explicit error handlers.
Fixes#895
`startswith` string comparison allows bypassing directory restrictions.
For example, `/home/user/workspace_evil` passes the check against
`/home/user/workspace` because the string starts with the allowed path.
Replace with `Path.relative_to()` which correctly validates that the
resolved path is actually inside the allowed directory tree.
Fixes#888
andienguyen-ecoligo