fix(ci): document squash-merge requirement to prevent orphaned tags

PyPI rejected 0.3.0 upload because the old orphaned release already
published that version. This commit triggers 0.3.1 release and
documents the squash-merge requirement that prevents recurrence.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: abrichr

.github/workflows/release.yml

@@ -1,5 +1,9 @@
 name: Release and PyPI Publish
 
+# IMPORTANT: This repo must use squash merges only. Non-squash merges can
+# orphan semantic-release's "chore: release" commit, breaking version detection.
+# Enforced via GitHub repo settings (allow_merge_commit=false, allow_rebase_merge=false).
+
 on:
   push:
     branches: