Overrides that stick, and messages every agent sees

Fixes from running Claude Code and omp side by side on one project. Update with comity update.

Fixed

Approved overrides stick. After an owner approves an override, the agent can make that change without being blocked again. A change outside what was approved still needs approval.

Messages reach every agent you have running. A message to you shows up in each of your live agent sessions, not just the first one to check in.

Work stays with the right intent. Switching branches or intents in one agent session no longer mixes their changes, which caused false conflicts.

Quieter and side-effect free. comity doctor no longer marks messages as read or announces you online, teammates get one "came online" notice instead of one per session, and the sender of a handoff now hears when it's picked up.