feat: add scheduled issue labeler for type/domain triage (#251)

* ci: add issue labeler workflow

Add a manual GitHub Actions workflow and script to poll issues and apply type/domain labels.

* feat(issue-labels): refine heuristics and add docs

Improve domain detection and add safeguards to avoid overriding manual type triage by default. Refresh regression samples from real issues and document usage.

* ci(issue-labels): enable hourly scheduled labeling

Run hourly on schedule with write mode by default while keeping manual dispatch dry-run by default.

* ci(issue-labels): shorten lookback window to 6h

Reduce scheduled scan window while keeping overlap for missed runs.

* ci(issue-labels): opt into Node 24 actions runtime

Set FORCE_JAVASCRIPT_ACTIONS_TO_NODE24 and use Node 24 for the script runtime to avoid upcoming Node 20 deprecation warnings.

* ci(issue-labels): restore lookback input for manual runs

Allow workflow_dispatch to override lookback_hours while keeping hourly schedule fixed.

* ci(issue-labels): upgrade checkout/setup-node to v6

Use actions/checkout@v6 and actions/setup-node@v6 to align with Node 24 runtime and avoid Node 20 deprecation warnings.

* fix(ci): label only unlabeled issues via search api

* fix(ci): refine issue labeling heuristics from live issues

* fix(ci): address remaining issue label review comments

* fix(ci): fix issue label arg parsing regression

* docs(issue-labels): clarify one-shot unlabeled triage scope

.github/workflows/issue-labels.yml

@@ -0,0 +1,57 @@
+name: Issue Labels
+
+on:
+  schedule:
+    - cron: '0 * * * *' # every hour
+  workflow_dispatch:
+    inputs:
+      dry_run:
+        description: "Do not write labels, only print planned changes"
+        required: false
+        default: true
+        type: boolean
+
+permissions:
+  contents: read
+  issues: write
+
+concurrency:
+  group: issue-labels
+  cancel-in-progress: true
+
+jobs:
+  sync-issue-labels:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      # v6+ uses Node 24 runtime for JavaScript actions.
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: '24'
+
+      - name: Sync managed issue labels
+        id: sync_issue_labels
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          EVENT_NAME: ${{ github.event_name }}
+          INPUT_DRY_RUN: ${{ github.event.inputs.dry_run }}
+        run: |
+          args=(
+            "--max-issues" "300"
+          )
+
+          # Schedule runs should write labels by default.
+          # Manual runs default to dry-run unless explicitly disabled.
+          if [ "$EVENT_NAME" = "workflow_dispatch" ] && [ "${INPUT_DRY_RUN:-true}" = "true" ]; then
+            args+=("--dry-run" "--json")
+          fi
+
+          node scripts/issue-labels/index.js "${args[@]}"
+
+      - name: Warn when label sync fails
+        if: ${{ always() && steps.sync_issue_labels.outcome == 'failure' }}
+        run: |
+          echo "::warning::Issue label sync failed; labels may be stale."
+          echo "⚠️ Issue label sync failed; labels may be stale." >> "$GITHUB_STEP_SUMMARY"