feat: improve CI and project automation workflows (#390)

- Harden docker/release workflow with manual release guardrails and concurrency
- Add stale issue cleanup workflow (issues only)
- Add project field sync workflow from issue labels
- Add weekly triage report workflow
- Add CODEOWNERS for automatic review routing

.github/workflows/close-inactive-issues.yml

@@ -0,0 +1,27 @@
+name: Close inactive issues
+
+on:
+  schedule:
+    - cron: "30 1 * * *"
+  workflow_dispatch:
+
+jobs:
+  close-issues:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+      - name: Mark and close stale issues
+        uses: actions/stale@v9
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          days-before-issue-stale: 30
+          days-before-issue-close: 14
+          stale-issue-label: stale
+          stale-issue-message: "This issue is stale because it has been open for 30 days with no activity."
+          close-issue-message: "This issue was closed because it has been inactive for 14 days since being marked as stale."
+          days-before-pr-stale: -1
+          days-before-pr-close: -1
+          exempt-issue-labels: pinned,security
+          operations-per-run: 200