feat(quality-gates): add baseline verification and acknowledged failures

- Add QualityGatesBaseline interface to track verified state
- Add QUALITY_GATES_VERIFY tool to run gates and establish baseline
- Add QUALITY_GATES_ACKNOWLEDGE tool to acknowledge pre-existing failures
- Add QUALITY_GATES_BASELINE_GET tool to check current baseline status
- Update agent prompt to differentiate between:
  - All gates passing: agent maintains this state
  - Acknowledged failures: agent ignores pre-existing issues

When failures are acknowledged, agents focus on their assigned task
without trying to solve the world by fixing unrelated issues.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: vibegui