Channel Operator Reliability Fixes

Fixed

• Fixed channel operator failing to orchestrate agents — the operator now explicitly loads channel tools before every run

• Fixed channel operator crashing when the configured model is unavailable — now auto-retries with the default Claude model with a status message

• Fixed channel silently failing when tools can't connect — falls back to sending messages directly to @mentioned agents

• Fixed channel tools not loading in production builds — missing dependency is now correctly bundled