Add build workflow

.github/workflows/build.yml

@@ -0,0 +1,54 @@
+name: build-plugin
+on:
+  workflow_dispatch:
+  push:
+    branches: [ main ]
+    paths:
+      - "src/**"
+      - Cargo.lock
+      - rust-toolchain.toml
+      - flake.nix
+      - flake.lock
+      - shell.nix
+
+  pull_request:
+    branches: [ main ]
+    paths:
+      - "src/**"
+      - Cargo.lock
+      - rust-toolchain.toml
+      - flake.nix
+      - flake.lock
+      - shell.nix
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        profile: [ "dev", "release" ]
+
+    env:
+      BUILD_NAME: ${{ matrix.profile == 'dev' && 'debug' || matrix.profile }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Nix
+        uses: nixbuild/nix-quick-install-action@v28
+
+      - name: Check
+        run: nix develop --command cargo clippy --profile ${{ matrix.profile }} -- -D warnings
+
+      - name: Build
+        run: nix develop --command cargo build --profile ${{ matrix.profile }}
+
+      - name: Upload build
+        uses: actions/upload-artifact@v4
+        with:
+          name: mpv-rpc_${{ env.BUILD_NAME }}
+          path: target/${{ env.BUILD_NAME }}/libmpv_rpc.so