ci: optimize self-hosted build — incremental Rust, drop Swatinem cache

.github/workflows/release.yml

@@ -60,10 +60,8 @@ jobs:
         with:
           targets: ${{ matrix.target }}
 
-      - name: Rust cache
-        uses: Swatinem/rust-cache@v2
-        with:
-          workspaces: src-tauri
+      # Self-hosted runner: cargo registry + target dir persist on disk between runs.
+      # No need for Swatinem/rust-cache — incremental builds kick in automatically.
 
       - name: Install frontend dependencies
         run: pnpm install --frozen-lockfile
@@ -78,6 +76,8 @@ jobs:
         env:
           TAURI_SIGNING_PRIVATE_KEY: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY }}
           TAURI_SIGNING_PRIVATE_KEY_PASSWORD: ""
+          # Incremental compilation — reuses previous build artifacts on self-hosted runner
+          CARGO_INCREMENTAL: "1"
         run: |
           pnpm tauri build --target ${{ matrix.target }}