docs: add critical CI drift fixation guide and update maintenance routine

docs/CI_DRIFT_FIX.md

@@ -0,0 +1,38 @@
+# CI Drift Fix Guide
+
+**Problem**: The failing job is caused by uncommitted changes detected in `README.md` or `skills_index.json` after the update scripts run.
+
+**Error**:
+
+```
+❌ Detected uncommitted changes in README.md or skills_index.json. Please run scripts locally and commit.
+```
+
+**Cause**:
+Scripts like `scripts/generate_index.py` and `scripts/update_readme.py` modify `README.md` and `skills_index.json`, but the workflow expects these files to have no changes after the scripts are run. Any differences mean the committed repo is out-of-sync with what the generation scripts produce.
+
+**How to Fix (DO THIS EVERY TIME):**
+
+1. Run the scripts locally to regenerate README.md and skills_index.json:
+
+   ```bash
+   python3 scripts/generate_index.py
+   python3 scripts/update_readme.py
+   ```
+
+2. Check for changes:
+
+   ```bash
+   git status
+   git diff
+   ```
+
+3. Commit and push any updates:
+   ```bash
+   git add README.md skills_index.json
+   git commit -m "Update README and skills index to resolve CI drift"
+   git push
+   ```
+
+**Summary**:
+Always commit and push all changes produced by the registry or readme update scripts. This keeps the CI workflow passing by ensuring the repository and generated files are synced.