feat: scheduled rebuild every 30 minutes

Picks up new content from IndieKit, refreshes external feeds (Last.fm,
Mastodon, Bluesky, Funkwhale, etc.) and redeploys without a manual push.

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

.github/workflows/deploy.yml

@@ -4,6 +4,8 @@ on:
   push:
     branches: [main]
   workflow_dispatch:
+  schedule:
+    - cron: "*/30 * * * *"
 
 jobs:
   build-and-deploy: