Allow custom PR watchers without conflicting runtime instructions

[ryuudotgg]

I use reusable skills with a CLI PR watcher across different coding tools. I'd like to keep that workflow when using T3 Code.

The instructions added in #15057 require the agent to use watch_pull_request, end its turn, and not run its own watcher. In my case, this overrides the CLI watcher specified by my project workflow.

Could native PR watching be opt-in through Settings? When disabled, the agent should not receive instructions requiring the native watcher or prohibiting another watcher.

Alternatively, if native watching should remain enabled by default, relaxing the instructions to respect an explicit user or project watcher choice would solve my problem too.

Either approach should preserve the functionality available before #15057, including PR linking and tracking.

[gabynevada]

Same, have an MCP that decides when to wake up agents but this update is breaking that workflow with no way to turn it off.