Add sync fork GitHub action workflow

Author: kfang4

.github/workflows/sync-fork.yml

@@ -0,0 +1,33 @@
+name: Sync Fork
+
+on:
+  schedule:
+    # Runs every week on Sunday at 2 AM UTC
+    - cron: '0 2 * * 0'
+  workflow_dispatch: # Allows manual triggering
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+        fetch-depth: 0
+
+    - name: Sync upstream
+      run: |
+        git config user.name "github-actions[bot]"
+        git config user.email "github-actions[bot]@users.noreply.github.com"
+        
+        git remote add upstream https://github.com/ASAP-CRN/spatial-transcriptomics-wf.git
+        
+        git fetch upstream
+        
+        # Merge upstream changes
+        git checkout main
+        git merge upstream/main
+        
+        git push origin main