fix: restore Copilot auth in Tutorial Update Monitor sandbox runs

.github/workflows/tutorial-update-monitor.md

@@ -79,10 +79,14 @@ Use the GitHub tool to list recent commits (last 14 days) from `github/copilot-c
      - Suggested changes or new content to add
    - Do **not** create an issue if a similar one already covers this topic in any state
 
+6. **REQUIRED — you must always finish by calling exactly one of these safe output tools:**
+   - Call `create_issue` for each new finding that passed the duplicate check (up to 5 issues)
+   - Call `noop` if all findings were duplicates or no meaningful changes were found — include a brief summary of what was checked
+
 ## Guidelines
 
 - Only create issues for **meaningful changes** that affect tutorial accuracy or completeness. Skip cosmetic or unrelated changes.
-- If no updates are found, call the `noop` tool with a brief summary of what was checked and confirming no updates were needed.
+- **You must always call at least one safe output tool** (`create_issue` or `noop`) before finishing. Finishing without calling either is an error.
 - Group closely related changes into a single issue when it makes sense.
 - Be specific and actionable in issue descriptions so maintainers can address them quickly.
 - Limit to **5 issues per run** to avoid noise.