docs: align review-reusable.yml header comments with the @v1 recommendation

PR #12's own review flagged that the reusable's own header still said pin
@<sha>/@main while the example+README now recommend @v1. Update the header
to recommend @v1 (or @<sha>) consistently.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/review-reusable.yml

@@ -6,7 +6,7 @@
 #   jobs:
 #     review:
 #       if: ...                      # actor gate for the comment trigger
-#       uses: steve/gadfly/.gitea/workflows/review-reusable.yml@<sha>
+#       uses: steve/gadfly/.gitea/workflows/review-reusable.yml@v1
 #       secrets:                     # forward ONLY what the reviewer needs
 #         OLLAMA_CLOUD_API_KEY:    ${{ secrets.OLLAMA_CLOUD_API_KEY }}
 #         CLAUDE_CODE_OAUTH_TOKEN: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
@@ -25,8 +25,9 @@
 #
 # Advisory only — never blocks a merge. The image is pinned to an immutable
 # :sha- tag here (act_runner caches :latest); bump it per Gadfly release.
-# Consumers should likewise pin `uses: ...@<sha>` (not @main) so a push to this
-# repo can't silently change the code that runs with their forwarded secrets.
+# Consumers should pin `uses: ...@v1` — a curated release tag moved on deliberate
+# releases, so central tuning here propagates without per-consumer edits — or a
+# full `@<sha>` for an immutable pin. Avoid `@main` (moves on every push).
 
 name: Gadfly review (reusable)