ci: build and deploy on sync-upstream branch

Adds sync-upstream to push triggers and relaxes the deploy job condition
so it fires on both main and sync-upstream. Deploy job still skips
pull_request events and all other branches.

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

Author: mdrokon-dev

.github/workflows/ci.yml

@@ -3,7 +3,7 @@ name: CI
 
 on:
   push:
-    branches: [ main ]
+    branches: [ main, sync-upstream ]
   pull_request:
     branches: [ main ]
 
@@ -28,7 +28,7 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     needs: build
-    if: github.ref == 'refs/heads/main' && github.event_name == 'push'
+    if: (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/sync-upstream') && github.event_name == 'push'
     permissions:
       contents: read
       packages: write