⬆️ Bump actions/stale from 3 to 10

[AnandChowdhary]

Summary

• Updates the scheduled stale workflow from actions/stale@v3 to @v10
• Adds explicit issue/PR write permissions and secrets.GH_PAT || github.token fallback where safe
• Repairs maintenance CI exposed by the PR: supported hosted runners for Node/Build CI, current checkout/setup-node pins, current labeler config/action, and a corrected PR-generator guard so the legacy PR action is skipped for non-feature branches

Supersedes the stale Dependabot PR #153.

Test plan

• Verified actions/stale@v10 still supports every configured workflow input
• Parsed changed workflow/config YAML with PyYAML
• Ran actionlint via stdin on changed workflows
• Compiled all actions/github-script script blocks with Node AsyncFunction
• Ran git diff --check
• Ran added-line security scan
• Ran Node 12/npm 6 validation: npm ci, npm run build, npm test -- --runInBand, npm pack --dry-run
• Ran Node 14/npm 6 npm ci, npm run build, npm run package and verified tracked dist/ stayed clean