feat: Add GitHub Actions workflows for CI/CD

- Add cross-platform build workflow for macOS, Windows, Linux
- Add CI workflow with Rust code quality checks
- Add manual release workflow with automatic asset publishing
- Add dependency management workflow with security monitoring
- Update README with build status badges
- Remove unused Prettier/ESLint configurations
- Focus on Rust code quality and build verification

.github/workflows/ci.yml

@@ -0,0 +1,99 @@
+name: CI
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  lint-and-test:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libwebkit2gtk-4.1-dev libappindicator3-dev librsvg2-dev
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 8
+
+      - name: Setup Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt, clippy
+
+      - name: Rust cache
+        uses: swatinem/rust-cache@v2
+        with:
+          workspaces: './src-tauri -> target'
+
+      - name: Install frontend dependencies
+        run: pnpm install
+
+      - name: Check Rust formatting
+        run: cargo fmt --all --check
+        working-directory: src-tauri
+
+      - name: Lint Rust code
+        run: cargo clippy --all-targets --all-features -- -D warnings
+        working-directory: src-tauri
+
+      - name: Run Rust tests
+        run: cargo test --all-features
+        working-directory: src-tauri
+
+      - name: Build frontend
+        run: pnpm build
+
+      - name: Check Tauri build
+        run: cargo check --all-targets --all-features
+        working-directory: src-tauri
+
+  security-audit:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Rust
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Install cargo-audit
+        run: cargo install cargo-audit
+
+      - name: Run security audit
+        run: cargo audit
+        working-directory: src-tauri
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 8
+
+      - name: Install frontend dependencies
+        run: pnpm install
+
+      - name: Run npm audit
+        run: pnpm audit --audit-level moderate