ci: add Rust GitHub Actions workflow (pipewire-only) and README badge

- Adds GitHub Actions workflow to run rustfmt, clippy, and tests on ubuntu-latest and installs PipeWire/WirePlumber packages.
- **Disables PipeWire** integration tests by default on CI via **_RUN_PIPEWIRE_INTEGRATION=false_** to avoid hardware probes on GitHub runners; tests may be enabled on self-hosted runners by setting _**RUN_PIPEWIRE_INTEGRATION.**_
- Adds a README badge for the new workflow.

## CI Status
✅ All checks passing:
- Code formatting (rustfmt)
- Linting (clippy) 
- Unit tests
- Integration tests (hardware-aware tests disabled in CI)

Author: Peter-L-SVK

.github/workflows/rust-ci.yml

@@ -0,0 +1,57 @@
+name: Rust CI (build, lint, test)
+
+on:
+  push:
+    branches: [ stage, main ]
+  pull_request:
+    branches: [ stage, main ]
+  workflow_dispatch:   # allow manual runs (useful to trigger full integration)
+    inputs:
+      run_integration:
+        description: 'Run PipeWire integration tests (requires suitable runner)'
+        required: false
+        default: 'false'
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Install system dependencies (GTK, ALSA, PipeWire, WirePlumber)
+        run: |
+          sudo apt-get update -y
+          sudo apt-get install -y build-essential pkg-config libglib2.0-dev libgtk-3-dev libasound2-dev libpipewire-0.3-dev pipewire wireplumber
+
+      - name: Set up Rust toolchain (actions-rs/toolchain)
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          components: rustfmt, clippy
+          override: true
+
+      - name: Cache Cargo and target
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-cargo-
+
+      - name: cargo fmt check
+        run: cargo fmt --all -- --check
+
+      - name: cargo clippy (warn only)
+        run: cargo clippy --all-targets --all-features
+
+      - name: Run tests
+        env:
+          CI: "true"
+          GITHUB_ACTIONS: "true"
+          RUN_PIPEWIRE_INTEGRATION: ${{ github.event.inputs.run_integration || 'false' }}
+        run: cargo test --workspace --all-features --verbose

README.md

@@ -1,5 +1,7 @@
 # Pro Audio Config
 
+[![Rust CI](https://github.com/Peter-L-SVK/pro_audio_config/actions/workflows/rust-ci.yml/badge.svg)](https://github.com/Peter-L-SVK/pro_audio_config/actions/workflows/rust-ci.yml)
+
 A professional audio configuration tool for Linux systems that provides a simple graphical interface to manage PipeWire and ALSA audio settings. Finally, an easy way to configure sample rates, bit depths, and buffer sizes without digging through config files.
 
 ## Why This Exists