[Suneha Bose (bosesuneha)]

Summary

• Grant the stale job issues: write and pull-requests: write so labels and comments are no longer blocked by token permissions.
• Mark issues and PRs idle after 60 inactive days, then close after 14 more inactive days. New activity clears idle and restarts the cycle.
• Use one stale-action step for both issues and PRs, preserving the backlog issue exemption and three-hour schedule.
• Add warning and closure messages explaining the policy.

Matches the 60 + 14 day timing in Azure/draft#801, but covers both issues and PRs.

Validation

• Configuration assertions for permissions, timing, messages, exemptions, activity reset, and schedule.
• actionlint, Prettier, and git diff --check passed.
• No live cleanup was triggered.

Rollout

Previously unlabeled items receive a warning and a 14-day grace period. Existing idle labels retain their history, so already-idle items may close on the first scheduled run.

Related: #572 also grants stale-job write permissions; this PR additionally enables cleanup and consolidates the two stale steps.