- Add `-path` force-exclude pattern (exact path match, highest precedence)
- Change `+path` force-include to exact path match (no glob)
- Manifest-excluded resources are now hidden from config (not toggleable)
- Config toggle uses `+` to enable and `-` to disable
- Settings paths resolve relative to settings.json location:
- Global: relative to ~/.pi/agent
- Project: relative to .pi
- Add baseDir to PathMetadata for proper relative path computation
- Update tests for new base directory and pattern behavior
fixes#951