Add assignment-helper workflow

Uses shared reusable workflow from kubestellar/infra.
Helps users who ask natural language questions about assignment.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Signed-off-by: Andrew Anderson <andy@clubanderson.com>

Author: clubanderson

.github/workflows/assignment-helper.yml

@@ -0,0 +1,9 @@
+name: Assignment Helper
+
+on:
+  issue_comment:
+    types: [created]
+
+jobs:
+  assignment-helper:
+    uses: kubestellar/infra/.github/workflows/reusable-assignment-helper.yml@main