Carry Bun compile cache into Tauri packaging

Tauri runs the repository beforeBuildCommand during packaging, which invokes build:sidecars again after the explicit sidecar step has already passed. The Windows runner therefore still needs the same Bun compile cache override inside the packaging step so the repeated baseline runtime extraction stays on the runner work drive.

Constraint: Tauri beforeBuildCommand re-enters the sidecar build under the packaging step environment.
Rejected: Remove beforeBuildCommand from CI | that would diverge CI from normal Tauri packaging behavior.
Confidence: high
Scope-risk: narrow
Directive: Keep explicit sidecar build and Tauri packaging environments in sync when changing desktop workflow target or cache settings.
Tested: bun test scripts/pr/release-workflow.test.ts; bun run check:policy
Not-tested: GitHub Actions Windows runner rerun after push.

.github/workflows/build-desktop-dev.yml

@@ -134,6 +134,7 @@ jobs:
       - name: Build Tauri app
         working-directory: desktop
         env:
+          BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache
           TAURI_ENV_TARGET_TRIPLE: ${{ matrix.rust_target }}
         run: |
           # 开发构建: 禁用 updater artifacts (不需要签名密钥)

.github/workflows/release-desktop.yml

@@ -166,7 +166,9 @@ jobs:
       - name: Build Tauri app
         uses: tauri-apps/tauri-action@v0
         env:
+          BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          TAURI_ENV_TARGET_TRIPLE: ${{ matrix.rust_target }}
           TAURI_SIGNING_PRIVATE_KEY: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY }}
           TAURI_SIGNING_PRIVATE_KEY_PASSWORD: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY_PASSWORD }}
         with:

scripts/pr/release-workflow.test.ts

@@ -17,16 +17,18 @@ describe('release desktop workflow', () => {
       '.github/workflows/release-desktop.yml',
     ]) {
       const workflow = readFileSync(workflowPath, 'utf8')
-      const buildSidecarsStep = workflow.match(
-        /- name: Build sidecars[\s\S]*?run: bun run build:sidecars/,
-      )?.[0]
+      for (const stepName of ['Build sidecars', 'Build Tauri app']) {
+        const step = workflow.match(
+          new RegExp(`- name: ${stepName}[\\s\\S]*?(?:\\n\\s{6}- name:|\\n\\s*# ──|\\n\\s*with:|$)`),
+        )?.[0]
 
-      expect(buildSidecarsStep, workflowPath).toContain(
-        'BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache',
-      )
-      expect(buildSidecarsStep, workflowPath).toContain(
-        'TAURI_ENV_TARGET_TRIPLE: ${{ matrix.rust_target }}',
-      )
+        expect(step, `${workflowPath} ${stepName}`).toContain(
+          'BUN_INSTALL_CACHE_DIR: ${{ runner.temp }}/bun-install-cache',
+        )
+        expect(step, `${workflowPath} ${stepName}`).toContain(
+          'TAURI_ENV_TARGET_TRIPLE: ${{ matrix.rust_target }}',
+        )
+      }
     }
   })
 })