feat: add GitHub Actions workflow for Supabase migration

.gitea/workflows/migrate_supabase.yaml

@@ -0,0 +1,24 @@
+name: Migrate supabase
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - '*'
+
+env:
+  DATABASE_URL: ${{ secrets.DATABASE_URL }}
+
+jobs:
+  migrate:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run migrations
+        run: npm run db:migrate