Add tracked AI skills for Blender assets and release QA

AGENTS.md

@@ -48,6 +48,19 @@ forces one.
 Use them when a task touches `tools/blender_assets.py`, `tools/npc_pipeline.py`,
 `tools/bake_ao.py`, `assets/models/blender/**`, or Blender-authored venue/prop geometry.
 
+### Project-authored skills (tracked)
+
+Two project skills are committed under `.agents/skills/` and are guidance for
+any agent, not only Pi:
+
+- `gig-line-blender-asset-contract` — the NPC/gear/prop contract, build order,
+  headless Blender commands, failure playbook and verification gates.
+- `gig-line-release-qa` — the test/smoke matrix, visual judges, clean-worktree
+  build, checksum/tag/publish sequence and release records.
+
+They are not runtime dependencies and do not move tool implementations into
+`.agents/`. The third-party `blender-skills` pack stays local/gitignored.
+
 ### Routing
 
 Start with `blender-director` for anything multi-discipline, then load only the