## Why
Executor-scoped cleanup hooks need to observe an interrupted turn as well as a
normally completed one.
## What changed
- Allow bundled executor plugins to register the allowlisted `Interrupt` hook
alongside `Stop`, while preserving multiple allowed hook entries from the
selected executor environment.
- Run interrupt hooks with the interrupted turn's last step discovery and turn
metadata. Turns without a step context do not reuse discovery from an earlier
turn.
- Keep executor-scoped interrupt hooks asynchronous and omit public hook
lifecycle events for them, matching executor `Stop` hook behavior.
## Testing
Added coverage for hook filtering and registration, interrupt execution and
metadata propagation, environment selection, and turns without a step context.
GitOrigin-RevId: f0c536b3382a37cf3bf693c4573d21f6f66ace4e
Krish Chainani
c2abf869d5