fix: replace actions/labeler with inline script to eliminate rate limiting

actions/labeler@v6 fetches the PR via API on every run, which silently
fails with 'Could not find pull request' when the installation rate
limit is exhausted. Replace it with an inline github-script that reads
the branch name directly from the event payload (zero API calls for
branch-name rules). The .github file-change check for the 'repo' label
is the only rule that needs an API call, and it's skipped when the
branch name already matches.

Also removes .github/labeler.yml which is no longer needed.

.github/labeler.yml

@@ -1,35 +0,0 @@
-# Auto Labeler rulse using https://github.com/actions/labeler
-#
-
-# 'fix' in title/branch -> bug
-# 'feat' in title/branch -> enhancement
-# 'repo' in title/branch OR changes to ~/.github/ -> repo
-# 'bug_fallthrough' for everything else except auto 
-#
-# - [ ] need to look at title.     waiting on https://github.com/actions/labeler/pull/866
-
-# Add 'enhancement' label to any PR where the head branch name contains `feat`
-enhancement:
- - head-branch: [feat, Feat, FEAT]
-
- # Add 'repo' label to any PR where the head branch name contains `repo` 
- # or files in the .github dir
-repo:
-- any:
-  - head-branch: [repo, Repo, REPO, ci, CI]
-  - changed-files:
-    - any-glob-to-any-file: .github
-
- # Add 'bug' label to any PR where the head branch name contains `fix` or `bug` as the prefix.
-bugfix:
-  - head-branch: [^fix, ^bug, ^Fix, ^FIX, ^Bug, ^BUG]
-
-# Add `refactor` label to any PR where the head branch name contains `refactor` or `Refactor` as the prefix.
-refactor:
-  - head-branch: [^refactor, ^Refactor]
-
-# our fallback - bug except repo, feat, or automated pipelines
-# bug_fallthrough:
-# - all:
-#   - head-branch: ['^((?!feat).)*$', '^((?!repo).)*$', '^((?!renovate).)*$', '^((?!scheduled).)*$']
-

.github/workflows/pull-request-target.yml

@@ -12,7 +12,48 @@ jobs:
       pull-requests: write
     runs-on: ubuntu-24.04-arm
     steps:
-    - id: label-the-PR
-      uses: actions/labeler@v6
+    - name: Auto-label PR
+      uses: actions/github-script@v8
       with:
-        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        script: |
+          const branch = context.payload.pull_request.head.ref;
+          const labels = new Set();
+
+          // enhancement: branch contains feat
+          if (/feat/i.test(branch)) labels.add('enhancement');
+
+          // bugfix: branch starts with fix or bug
+          if (/^(fix|bug)/i.test(branch)) labels.add('bugfix');
+
+          // refactor: branch starts with refactor
+          if (/^refactor/i.test(branch)) labels.add('refactor');
+
+          // repo: branch contains repo or ci
+          if (/repo|ci/i.test(branch)) {
+            labels.add('repo');
+          } else {
+            // Also label 'repo' if .github files were changed (needs one API call)
+            try {
+              const files = await github.paginate(
+                github.rest.pulls.listFiles,
+                { owner: context.repo.owner, repo: context.repo.repo, pull_number: context.payload.pull_request.number, per_page: 100 },
+                (res) => res.data.map(f => f.filename)
+              );
+              if (files.some(f => f.startsWith('.github/'))) labels.add('repo');
+            } catch (e) {
+              core.warning(`Could not list PR files (rate limited?): ${e.message}`);
+            }
+          }
+
+          if (labels.size > 0) {
+            const labelArray = [...labels];
+            core.info(`Applying labels: ${labelArray.join(', ')}`);
+            await github.rest.issues.addLabels({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.payload.pull_request.number,
+              labels: labelArray,
+            });
+          } else {
+            core.info('No labels matched for this PR.');
+          }