chore: add upstream sync workflow

Author: sangjanai

.github/workflows/upstream-sync.yml

@@ -0,0 +1,45 @@
+name: Sync with Latest Release
+
+on:
+  schedule:
+    - cron: '0 0 * * *'  # Runs daily at midnight UTC
+  workflow_dispatch:     # Allow manual triggering
+
+jobs:
+  sync-with-release:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout repo
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0  # Get full history for commit count
+
+    - name: Add upstream remote
+      run: |
+        git remote add upstream https://github.com/ggml-org/llama.cpp.git
+        git fetch upstream --tags  # Fetch tags from upstream
+
+    - name: Sync master with latest release
+      run: |
+        git checkout master
+        LATEST_RELEASE=$(git describe --tags --abbrev=0 upstream/master)
+        git reset --hard $LATEST_RELEASE
+        git push origin master --force
+
+    - name: Rebase dev onto master
+      run: |
+        git checkout dev
+        if ! git rebase master; then
+            echo "Rebase conflict detected, aborting"
+            git rebase --abort
+            exit 1
+        fi
+        git push origin dev --force-with-lease
+
+    - name: Create version tag
+      run: |
+        git checkout master
+        COMMIT_COUNT=$(git rev-list --count HEAD)
+        git checkout dev
+        git tag "b${COMMIT_COUNT}"
+        git push origin tag "b${COMMIT_COUNT}"