ci(stale): enable 35+35 stale/close policy for pull requests (#3375)

* ci(stale): enable 28+28 stale/close policy for pull requests

- Fix the repository guard so the workflow actually runs on
  QwenLM/qwen-code (it was previously gated to google-gemini/gemini-cli
  and never executed in this repo).
- Scope the behavior to pull requests for now; issue policy will be
  introduced separately once triage labels are in place.
- Mark a PR stale after 4 weeks without activity, then close it after
  another 4 weeks.
- Exempt pinned, security, status/blocked, status/on-hold, and
  status/ready-for-merge from auto-close.
- Remove the stale label automatically when activity resumes, and
  process the oldest PRs first on each run.

* ci(stale): loosen PR cadence from 28+28 to 35+35

Five weeks + five weeks gives contributors more slack around holidays
and busy periods, and reduces the first-run impact on the existing
backlog. The total window moves from 56 days to 70 days.

* ci(stale): move cron from 01:30 UTC to 00:30 UTC

Shift by one hour so results are ready before the Beijing work day
starts (08:30 local), while still avoiding the top of the hour (the
high-contention window for GitHub-hosted runners) and staying 30
minutes after release.yml at 00:00 UTC.

* ci(stale): drop redundant repo guard and document ops-per-run

- Remove the `github.repository == 'QwenLM/qwen-code'` job guard:
  scheduled runs are already disabled on forks by GitHub, and
  workflow_dispatch is manually-triggered so the guard adds no safety.
- Add a comment explaining the `operations-per-run: 100` rationale
  (rate-limit headroom given the ~150-PR backlog).

.github/workflows/stale.yml

@@ -1,16 +1,16 @@
 name: 'Mark stale issues and pull requests'
 
-# Run as a daily cron at 1:30 AM
+# Run as a daily cron at 00:30 UTC (Beijing time 08:30).
+# Avoid the top of the hour to dodge GitHub's high-contention window,
+# and stay 30 minutes after release.yml (00:00 UTC) to reduce overlap.
 on:
   schedule:
-    - cron: '30 1 * * *'
+    - cron: '30 0 * * *'
   workflow_dispatch:
 
 jobs:
   stale:
     runs-on: 'ubuntu-latest'
-    if: |-
-      ${{ github.repository == 'google-gemini/gemini-cli' }}
     permissions:
       issues: 'write'
       pull-requests: 'write'
@@ -21,19 +21,27 @@ jobs:
       - uses: 'actions/stale@5bef64f19d7facfb25b37b414482c7164d639639' # ratchet:actions/stale@v9
         with:
           repo-token: '${{ secrets.GITHUB_TOKEN }}'
-          stale-issue-message: >-
-            This issue has been automatically marked as stale due to 60 days of inactivity.
-            It will be closed in 14 days if no further activity occurs.
+          # Issues are intentionally disabled here; a separate policy will
+          # be introduced once issue triage labels are in place.
+          days-before-issue-stale: -1
+          days-before-issue-close: -1
+          # Pull requests: 60 days to stale + 30 days to close.
+          days-before-pr-stale: 60
+          days-before-pr-close: 30
+          stale-pr-label: 'status/stale'
           stale-pr-message: >-
-            This pull request has been automatically marked as stale due to 60 days of inactivity.
-            It will be closed in 14 days if no further activity occurs.
-          close-issue-message: >-
-            This issue has been closed due to 14 additional days of inactivity after being marked as stale.
-            If you believe this is still relevant, feel free to comment or reopen the issue. Thank you!
+            This pull request has had no activity for 60 days and is being marked as stale.
+            It will be closed in another 30 days if no further activity occurs.
+            To keep it open, push a new commit or leave a comment.
+            Maintainers may apply `pinned`, `status/blocked`, `status/on-hold`,
+            or `status/ready-for-merge` to exempt it from auto-close.
           close-pr-message: >-
-            This pull request has been closed due to 14 additional days of inactivity after being marked as stale.
-            If this is still relevant, you are welcome to reopen or leave a comment. Thanks for contributing!
-          days-before-stale: 60
-          days-before-close: 14
-          exempt-issue-labels: 'pinned,security'
-          exempt-pr-labels: 'pinned,security'
+            This pull request has been closed after 30 additional days of inactivity.
+            You are welcome to reopen it or submit a new pull request if the change is still relevant.
+            Thanks for contributing!
+          exempt-pr-labels: 'pinned,security,status/blocked,status/on-hold,status/ready-for-merge'
+          remove-stale-when-updated: true
+          ascending: true
+          # Cap per-run API operations to stay well under GitHub's hourly rate limit
+          # and give the current PR backlog (~150) enough headroom across a few runs.
+          operations-per-run: 100