🚦 ci: Stop Auto-Indexing PR Branches in GitNexus Index (#13866)

.github/workflows/gitnexus-index.yml

@@ -1,12 +1,13 @@
 name: GitNexus Index
 
 on:
+  # PR branches are NOT auto-indexed — an embeddings run is too slow to
+  # spend on every PR push. Only main/dev are indexed automatically;
+  # individual PRs are indexed on demand via the /gitnexus command or a
+  # manual workflow_dispatch.
   push:
     branches: [main, dev]
     paths-ignore: ['**.md', 'docs/**', 'LICENSE', '.github/**']
-  pull_request:
-    branches: [main, dev]
-    paths-ignore: ['**.md', 'docs/**', 'LICENSE', '.github/**']
   workflow_dispatch:
     inputs:
       embeddings:
@@ -50,15 +51,13 @@ jobs:
     permissions:
       contents: read
       pull-requests: read # read changed files to decide whether embeddings are needed
-    # Push + dispatch run unconditionally. Native pull_request events
-    # are restricted to PRs authored by danny-avila only — this keeps
-    # automatic CI spend low on a repo with 200+ open PRs.
-    #
-    # Other contributors' PRs can still be indexed on demand:
+    # Push + dispatch run unconditionally. The pull_request trigger is
+    # disabled (see `on:` above), so this never runs automatically on a
+    # PR. PRs are indexed on demand instead:
     #   - /gitnexus index    (PR comment command, contributor-gated)
     #   - workflow_dispatch   (manual dispatch from Actions UI)
-    # Both bypass this filter because they arrive as workflow_dispatch,
-    # not pull_request.
+    # Both arrive as workflow_dispatch. The pull_request guard is kept as
+    # a safety net should the trigger ever be re-added.
     if: |
       github.event_name != 'pull_request' ||
       github.event.pull_request.user.login == 'danny-avila'