/checkpoint

Save session progress - commits, pushes, creates/updates PR, archives completed features

Create a checkpoint of the current session:

## Phase 1: Update Progress

1. Update `.claude-harness/claude-progress.json` with:
   - Summary of what was accomplished this session
   - Any blockers encountered
   - Recommended next steps
   - Update lastUpdated timestamp

## Phase 1.5: Capture Working Context

1.5. Update `.claude-harness/working-context.json` with current working state:
   - Read `.claude-harness/feature-list.json` to identify active feature (first with passes=false)
   - Set `activeFeature` to the feature ID and `summary` to feature name
   - Populate `workingFiles` from:...