fix(ci): 修复workflow YAML语法错误导致Actions不触发

notify步骤多行字符串第二行未缩进，YAML解析失败，
Gitea忽略整个workflow，push不生成run。改为单行命令。

.gitea/workflows/miniapp-preview.yml

@@ -103,10 +103,7 @@ jobs:
           DISCORD_WEBHOOK_URL: ${{ secrets.DISCORD_WEBHOOK_URL }}
         run: |
           VERSION="$(tr -d '\n' < mini/ci-artifacts/resolved-version.txt)"
-          bash .gitea/scripts/notify.sh success \
+          bash .gitea/scripts/notify.sh success "小程序开发版上传成功" "版本: ${VERSION} 上传结果已保存到: /opt/lunar/ci-artifacts/miniapp-upload-latest.json"
-            "小程序开发版上传成功" \
-            "版本: ${VERSION}
-上传结果已保存到: /opt/lunar/ci-artifacts/miniapp-upload-latest.json"
       
       - name: Send failure notification
         if: failure()