[model-gateway] add llava model image processor and tests (#14371)

.github/workflows/pr-test-rust.yml

@@ -115,6 +115,12 @@ jobs:
           rustup toolchain install nightly --profile minimal
           cargo +nightly fmt -- --check
 
+      - name: Generate vision golden fixtures
+        run: |
+          pip install transformers pillow numpy
+          cd sgl-router/
+          python scripts/generate_vision_golden.py
+
       - name: Run Rust tests
         timeout-minutes: 20
         run: |