- Wrap _sync_loop sync() call with asyncio.wait_for(timeout=45s) to guard
against TCP-level hangs that the Matrix long-poll timeout cannot catch
- Add logger.debug at the top of _on_room_message so LOG_LEVEL=DEBUG
confirms whether callbacks fire at all (diagnoses #5819, #7914, #12614)
- Add logger.debug when MATRIX_REQUIRE_MENTION silently drops a message,
pointing users to the env var to disable the filter
Adapted for current mautrix-python adapter (PR was written against the
legacy matrix-nio adapter).
Closes#5819
f223346eb7