[misc] Add labeler for automatic labeling (#12710)

.github/workflows/labeler.yml

@@ -0,0 +1,19 @@
+name: Auto Label PRs
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  label:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/labeler@v5
+        with:
+          repo-token: "${{ secrets.GITHUB_TOKEN }}"
+          configuration-path: .github/labeler.yml
+          sync-labels: true

.github/workflows/lint.yml

@@ -32,3 +32,19 @@ jobs:
           extensions: h,c,cpp,hpp,cu,cuh,cc
           clangFormatVersion: 18
           style: file
+
+      - name: Check proto files are in sync
+        run: |
+          if ! diff -q python/sglang/srt/grpc/sglang_scheduler.proto sgl-router/src/proto/sglang_scheduler.proto; then
+            echo "❌ ERROR: Proto files are out of sync!"
+            echo ""
+            echo "The following files must be kept identical:"
+            echo "  - python/sglang/srt/grpc/sglang_scheduler.proto"
+            echo "  - sgl-router/src/proto/sglang_scheduler.proto"
+            echo ""
+            echo "Please ensure both files have the same content."
+            echo ""
+            echo "Differences:"
+            diff python/sglang/srt/grpc/sglang_scheduler.proto sgl-router/src/proto/sglang_scheduler.proto || true
+            exit 1
+          fi