Add progress dashboard, smart rollback, and proactive detection to --green

Implements three major developer experience enhancements:

Progress Dashboard:
- Real-time ETA estimation based on historical session data
- Phase tracking (local-checks, commit-and-push, ci-monitoring)
- Periodic progress updates during long-running operations
- Historical learning from past workflow durations

Smart Rollback System:
- Git SHA-based snapshot creation before each fix attempt
- Instant rollback capability via snapshot restoration
- Automatic cleanup of snapshots older than 7 days
- Snapshot listing at workflow completion

Proactive Pre-Commit Detection:
- Optional AI-powered scan for potential CI failures
- Detects type errors, lint violations, breaking changes
- Checks for debug artifacts (console.log, debugger, .only/.skip)
- Confidence scoring for early issue detection

Author: jdalton