ci: SKILL.md freshness check on push/PR + TODO updates

- .github/workflows/skill-docs.yml: fails if generated SKILL.md files are stale
- TODO.md: add E2E cost tracking and model pinning to future ideas

.github/workflows/skill-docs.yml

@@ -0,0 +1,11 @@
+name: Skill Docs Freshness
+on: [push, pull_request]
+jobs:
+  check-freshness:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: oven-sh/setup-bun@v2
+      - run: bun install
+      - run: bun run gen:skill-docs
+      - run: git diff --exit-code || (echo "Generated SKILL.md files are stale. Run: bun run gen:skill-docs" && exit 1)

TODO.md

@@ -103,6 +103,8 @@
   - [ ] Trend tracking across QA runs — compare baseline.json over time, detect regressions (P2, S)
   - [ ] CI/CD integration — `/qa` as GitHub Action step, fail PR if health score drops (P2, M)
   - [ ] Accessibility audit mode — `--a11y` flag for focused accessibility testing (P3, S)
+  - [ ] E2E test cost tracking — track cumulative API spend, warn if over threshold (P3, S)
+  - [ ] E2E model pinning — pin E2E tests to claude-sonnet-4-6 for cost efficiency, add retry:2 for flaky LLM (P2, XS)
 
 ## Ideas & Notes
   - Browser is the nervous system — every skill should be able to see, interact with, and verify the web