Add a new agent-driven skill that syncs delta specs from a change to main specs
without requiring archiving. This enables:
- Updating main specs during active development
- Intelligent merging (partial updates, adding scenarios)
- Idempotent operation (safe to run multiple times)
Implementation:
- Extract shared specs-apply logic from archive.ts to specs-apply.ts
- Add getSyncSpecsSkillTemplate and getOpsxSyncCommandTemplate
- Register /opsx:sync in artifact-experimental-setup
- Add specs-sync-skill main spec