fix(logging): alias stdlib RotatingFileHandler to concurrent-log-handler (#44873)

[tuancookiez-hub]

Replaces the overengineered #44904 with a much smaller version.

Summary

On Windows, stdlib RotatingFileHandler.doRollover() fails with PermissionError [WinError 32] whenever another process holds an append-mode handle on agent.log (always the case in Hermes — TUI, gateway, hy_memory server, MCP servers, and on-demand CLI commands all log from separate processes). Aliasing the import to concurrent_log_handler.ConcurrentRotatingFileHandler wraps the rename in a cross-process file lock (msvcrt on Windows, fcntl on POSIX) so only one process rotates at a time and the others wait their turn.

Changes (3 source files, 1 auto-generated lock)

• hermes_logging.py — alias the import to CLH. The as RotatingFileHandler alias keeps every existing isinstance(h, RotatingFileHandler) check in this module working unchanged.
• pyproject.toml — exact-pinned concurrent-log-handler==0.9.29 dep
• uv.lock — lock entry (auto-generated)
• tests/test_hermes_logging.py — same alias in the test file so the autouse fixture's isinstance(h, RotatingFileHandler) checks strip the new CLH-backed handlers between tests

Verification

Multi-process repro (the actual failure mode on Windows — separate processes each with their own FD on the file):

20 interleaved emits across 2 independent _ManagedRotatingFileHandler instances on the same file → 0 exceptions, 0 stderr, clean rotation producing .1 / .2 / .3 backups + .__agent.lock sidecar.

Multi-thread repro (8-thread variant — also passes, validates the same fix from a single-process angle):

8 threads × 80 emits (640 records) at maxBytes=256: 3 backup files created, 0 errors, 0 stderr tracebacks.

Test suite

60/62 pass on Windows. The 2 test_managed_mode_* failures are pre-existing and unrelated: _chmod_if_managed in hermes_logging.py doesn't actually os.chmod (the function body only creates the file if it doesn't exist; the class docstring claims it applies chmod 0660 but no such call exists in the file). On Windows this fails because os.chmod doesn't set Unix permission bits; on Linux it would fail because the umask-corrected default mode is 0o644, not 0o660. Happy to file a follow-up that adds the missing os.chmod(path, 0o660) to _chmod_if_managed and adjusts the test.

[teknium1]

Thanks for the focused Windows rotation fix. This has already been salvaged into current main and completed with the necessary platform guard.

• Automated hermes-sweeper review verified commit 394cdf48ce2702de224dc95ae73f663076d043bd (fix(logging): alias RotatingFileHandler to concurrent-log-handler (salvage #44921) (#46794)), which preserves contributor credit.
• Current hermes_logging.py:64-69 aliases ConcurrentRotatingFileHandler only on Windows and keeps stdlib RotatingFileHandler on POSIX.
• Current pyproject.toml:140 scopes concurrent-log-handler to sys_platform == 'win32'; the salvage commit documents that the unconditional version regressed POSIX managed-mode permissions and eager creation.
• The salvage commit is contained in release tag v2026.6.19.

Closing as implemented on main.