Add build-linux-ts-native workflow

.github/workflows/build-linux-ts-native.yml

@@ -0,0 +1,47 @@
+name: Build Linux java-tree-sitter native (.so)
+
+on:
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install build tools
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential cmake git openjdk-17-jdk-headless
+
+      - name: Clone java-tree-sitter 1.9.1
+        run: |
+          git clone --depth 1 --branch 1.9.1 \
+            https://github.com/seart-group/java-tree-sitter.git java-tree-sitter
+
+      - name: Build native library
+        run: |
+          cd java-tree-sitter
+          # The native CMake target produces libjava-tree-sitter.so
+          cmake -B build \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DCMAKE_C_FLAGS="-O2" \
+            -DJTREESITTER_BUILD_SHARED_LIBS=ON
+          cmake --build build --target java-tree-sitter -- -j$(nproc)
+          # Find the .so wherever CMake placed it
+          find build -name "libjava-tree-sitter.so"
+
+      - name: Copy to libs/linux-x64/
+        run: |
+          mkdir -p libs/linux-x64
+          find java-tree-sitter/build -name "libjava-tree-sitter.so" \
+            -exec cp {} libs/linux-x64/ \;
+          echo "Built:"
+          file libs/linux-x64/libjava-tree-sitter.so
+          ldd  libs/linux-x64/libjava-tree-sitter.so
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: linux-ts-native
+          path: libs/linux-x64/libjava-tree-sitter.so
+          retention-days: 90