ci: fire workflow on tag pushes too

The publish job is gated by `if: startsWith(github.ref, 'refs/tags/v')`
but the workflow's `on:` block only listed `push: branches: [main]`,
so tag pushes (`git push --tags`) didn't fire any workflow at all and
the publish gate never had a chance to evaluate. Adding `tags: ['v*']`
to the push trigger so the tag-fired job lands on the publish path.

Caught after the v0.2.0 tag push silently produced no Actions run.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: tylnexttime

.github/workflows/ci.yml

@@ -3,6 +3,7 @@ name: CI
 on:
   push:
     branches: [main]
+    tags: ['v*']    # tag pushes (v0.2.0, v0.3.0, …) trigger the publish job below
   pull_request:
     branches: [main]