fix(docker): flush config.json to the KSM record on container shutdown

[mani-muon]

Problem

When the entrypoint runs with --ksm-config/--ksm-token and --record, it starts docker_ksm_utility.py monitor in the background to push changes to config.json back to the KSM record. The monitor only uploads on its 30-second tick (MONITOR_INTERVAL=30). On container stop, cleanup_on_exit -> stop_config_monitor kills the monitor without a final upload, so anything written to config.json since the last tick is lost. Commander rotates clone_code on every login, so the next container start resumes from a stale config.

Fix

In stop_config_monitor, call the existing upload_config_to_ksm helper once before killing the monitor PID. The call only runs when KSM mode is active (KSM_CONFIG or KSM_TOKEN set, RECORD set, config.json present), and a failing upload is logged but does not block shutdown.

• No new helpers; reuses upload_config_to_ksm as it stands.
• MONITOR_INTERVAL is unchanged; this only adds a flush on shutdown.
• The config-file and user/password auth paths are untouched: the guard skips when no monitor was started.

Testing

Local harness with a stubbed python3 on PATH that records its argv and sleeps for monitor subcommands:

1. KSM mode, config present: stop_config_monitor invokes upload exactly once, then kills the monitor PID.
2. Same, with the upload stub exiting non-zero: a warning is logged and shutdown completes with rc 0.
3. Non-KSM path (no monitor started): no-op, no upload.
4. Monitor PID file present but KSM variables unset: the PID is still killed, no upload.

bash -n docker-entrypoint.sh is clean.

[mani-muon]

Hey @sk-keeper 👋🏽 -- May I please get a review on this PR? 🙇🏽