ci: 修复Android APK构建前置步骤

在 CI 的 APK 构建任务中增加 expo prebuild 以生成 android 工程，避免仓库未包含原生目录时构建失败。

Made-with: Cursor

.gitea/workflows/build.yml

@@ -118,6 +118,9 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
+      - name: Generate Android native project
+        run: npx expo prebuild --platform android --non-interactive
+
       - name: Build Android release APK
         run: |
           cd android
@@ -144,8 +147,8 @@ jobs:
         uses: docker/login-action@v3
         with:
           registry: ${{ env.REGISTRY }}
-          username: ${{ secrets.REGISTRY_USERNAME }}
-          password: ${{ secrets.REGISTRY_PASSWORD }}
+          username: ${{ secrets.GIT_USERNAME }}
+          password: ${{ secrets.GIT_TOKEN }}
 
       - name: Extract metadata for Docker
         id: meta