fix(pi-gauntlet): address review feedback — timeout outcomes, settle safety, state validation

- record pi.exec rejections (timeouts) as failed check outcomes instead of
  escaping runChecks; aborts still propagate so the loop pauses
- settle() never rejects into the agent_settled handler: unexpected errors
  stop the loop and surface through a new hooks.error notification
- parseStateEntry validates iteration (non-negative integer) and drops
  malformed result outcomes that would crash report rendering
- pin @parke.dev/pi-ext-config to ^0.1.0 like other internal consumers
- don't cache a rejected config promise; retry on next call
- type gauntlet tool params from the schema instead of any
- notify when commands run before the engine is initialized
- extract shared checkLine helper in report.ts