feat: Update PR label from description template (#27)

* feat: update PR label from template

- Search the PR text for checkboxes marked in the format [x] release:...``
- Only accepts these labels (the same as the pull_request_template.md template): release:major, release:feature, release:patterns, release:api, release:data, release:privacy, release:fix, release:docs, release:infra, release:security

- The job fails if more than one release:* is checked
 - Removes other old release:* from the PR and adds only the chosen one (keeps “exactly one” in sync)

* fix(ci): run auto-labeler on pull_request_target

---------

Co-authored-by: bruno cesar <brunoclz@brunos-MacBook-Pro.local>

.github/workflows/auto-label.yml

@@ -0,0 +1,96 @@
+name: Auto Labeler via PR Description
+
+on:
+  # pull_request_target is required to write labels on PRs from forks.
+  pull_request_target:
+    types: [opened, edited, synchronize, reopened, ready_for_review]
+
+jobs:
+  apply-labels:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: read
+      issues: write # PR labels are managed via the Issues API.
+      
+    steps:
+      - name: Read description and apply labels
+        uses: actions/github-script@v7
+        with:
+          script: |
+            // Only apply labels that exist in .github/pull_request_template.md
+            // Change type (choose one release label from taxonomy):
+            const allowedReleaseLabels = new Set([
+              'release:major',
+              'release:feature',
+              'release:patterns',
+              'release:api',
+              'release:data',
+              'release:privacy',
+              'release:fix',
+              'release:docs',
+              'release:infra',
+              'release:security',
+            ]);
+
+            const body = context.payload.pull_request.body || '';
+            if (!body.trim()) return;
+
+            // Matches: - [x] `release:major`
+            const checkedReleaseLabelRegex = /\[x\]\s*`(release:[^`]+)`/gi;
+            const selected = [];
+            let match;
+            while ((match = checkedReleaseLabelRegex.exec(body)) !== null) {
+              const label = (match[1] || '').trim();
+              if (allowedReleaseLabels.has(label)) selected.push(label);
+            }
+
+            const uniqueSelected = [...new Set(selected)];
+            if (uniqueSelected.length === 0) {
+              console.log('No release label selected in PR template; skipping.');
+              return;
+            }
+
+            if (uniqueSelected.length > 1) {
+              throw new Error(
+                `Multiple release labels selected: ${uniqueSelected.join(', ')}. Select exactly one.`
+              );
+            }
+
+            const chosen = uniqueSelected[0];
+            const owner = context.repo.owner;
+            const repo = context.repo.repo;
+            const issue_number = context.issue.number;
+
+            // Sync: remove other release:* labels from the allowed set, then add the chosen one.
+            const { data: existing } = await github.rest.issues.listLabelsOnIssue({
+              owner,
+              repo,
+              issue_number,
+            });
+
+            const existingReleaseLabels = existing
+              .map(l => l.name)
+              .filter(name => allowedReleaseLabels.has(name));
+
+            const toRemove = existingReleaseLabels.filter(name => name !== chosen);
+            for (const name of toRemove) {
+              await github.rest.issues.removeLabel({
+                owner,
+                repo,
+                issue_number,
+                name,
+              });
+              console.log(`Removed label: ${name}`);
+            }
+
+            if (!existingReleaseLabels.includes(chosen)) {
+              await github.rest.issues.addLabels({
+                owner,
+                repo,
+                issue_number,
+                labels: [chosen],
+              });
+              console.log(`Added label: ${chosen}`);
+            } else {
+              console.log(`Label already present: ${chosen}`);
+            }