ci: auto-label feature requests with the enhancement label (#28531)

.github/workflows/issue-label.yaml

@@ -67,3 +67,73 @@ jobs:
               issue_number: issue.number,
               labels: ['bug']
             });
+
+  label-feature-requests:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Add "enhancement" label to unlabeled feature requests
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const issue = context.payload.issue;
+
+            if (issue.labels.some((label) => label.name === 'enhancement')) {
+              return;
+            }
+
+            // A human (or the bug form) already classified this as a bug;
+            // do not stack a second, contradictory classification on it.
+            if (issue.labels.some((label) => label.name === 'bug')) {
+              return;
+            }
+
+            const isEdit = context.payload.action === 'edited';
+            const titleWasEdited = Boolean(context.payload.changes?.title);
+
+            if (isEdit && !titleWasEdited) {
+              return;
+            }
+
+            const title = issue.title ?? '';
+            const body = issue.body ?? '';
+
+            // Feature requests: "feat: ...", "feature: ...", "feature request: ...",
+            // "enhancement: ...", "enh: ...", "[Feature Request] ..." — the feature
+            // request form titles every submission "feat: ", so form submissions are
+            // covered by the same pattern.
+            const featureLikeTitle =
+              /^\s*(\[\s*(feat|feature|enhancement|enh)\b[^\]]*\]|(feat|feature( request)?|enhancement|enh)\s*[:/\-])/i.test(
+                title
+              );
+
+            // API/CLI-created issues that reproduce the feature request form structure.
+            // Only headings distinctive to that form.
+            const featureFormBody = /###\s*(Proposed Solution|Alternatives Considered)/i.test(body);
+
+            if (!featureLikeTitle && !featureFormBody) {
+              return;
+            }
+
+            if (isEdit) {
+              const events = await github.paginate(github.rest.issues.listEvents, {
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: issue.number,
+                per_page: 100
+              });
+
+              const enhancementLabelWasRemoved = events.some(
+                (event) => event.event === 'unlabeled' && event.label?.name === 'enhancement'
+              );
+
+              if (enhancementLabelWasRemoved) {
+                return;
+              }
+            }
+
+            await github.rest.issues.addLabels({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: issue.number,
+              labels: ['enhancement']
+            });