v0.4.1

Added

• Session auto-refresh on update: when the ai c session loop detects a version change after ai update, the bash template is reloaded via ai internal refresh-template and exec-replaced in the same shell. No user action required; mosh-safe. (AI-CLI-39)
• ai sync subcommands: push, pull, conflicts, watch — each exposed as a Click subcommand with --help at the subcommand level. (AI-CLI-47)

Fixed

• _auto_update_if_stale now uses an O_CREAT|O_EXCL lockfile instead of a stamp-file read/write race. Prevents double-update on concurrent session launches.
• transport.py deferred import from .main import _ensure_circusd was left over after the module split; updated to from .process_manager import _ensure_circusd. Caused a test regression where the function was imported before the patch was applied.
• Pyright type error: entry.value (bytes | None) in quota.py now guarded with if entry.value is not None before json.loads.
• Architecture doc updated: monolithic main.py dispatch → Click command group dispatch; ai tunnel open|close → start|stop; handoff publisher attribution corrected to handoff.py.
• Integration tests for _do_session_launch now use libtmux directly for has-session / new-session instead of subprocess rerouting, fixing failures in non-interactive CI environments.

Refactored

• main.py split into 8 modules (config, handoff, iterm2, layout, process_manager, session, session_script, transport); main.py reduced from ~4 000 to ~1 900 lines. All patch targets in tests updated to owning modules. (AI-CLI-39, AI-CLI-47)
• NATS callback closures extracted to module-level functions (_on_handoff_signal_watch, _write_pending_if_claimed_drain, _on_quota_snapshot_handler) so they can be unit-tested without a live NATS server. (AI-CLI-17)