Allow parallel CI runs by default with optional serialization

- Default concurrency group uses run_id (unique per run, no blocking)
- Set repo variable CI_SERIAL=true to serialize runs per branch
- Set CI_CANCEL_IN_PROGRESS=true to cancel older runs when new queued
- Document concurrency behavior and variables in README and guide

Made-with: Cursor

Author: Hongwei-MB

.github/workflows/ci.yml

@@ -11,8 +11,8 @@ permissions:
   contents: read
 
 concurrency:
-  group: ci-release-${{ github.ref }}
-  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+  group: ${{ vars.CI_SERIAL == 'true' && format('ci-release-{0}', github.ref) || format('ci-release-{0}', github.run_id) }}
+  cancel-in-progress: ${{ vars.CI_CANCEL_IN_PROGRESS == 'true' }}
 
 env:
   DOTNET_NOLOGO: true

README.md

@@ -144,6 +144,19 @@ env:
 
 ---
 
+## Concurrency
+
+Multiple `CI and Release` runs execute **in parallel by default**. Each run gets a unique `run_number`, so versions never conflict.
+
+To serialize runs on the same branch (only one active at a time), set repository variables in **Settings > Secrets and variables > Actions > Variables**:
+
+| Variable | Default | Effect |
+|----------|---------|--------|
+| `CI_SERIAL` | _(unset / false)_ | Set to `true` to queue runs per branch instead of running in parallel |
+| `CI_CANCEL_IN_PROGRESS` | _(unset / false)_ | Set to `true` to cancel the running workflow when a newer one is queued |
+
+---
+
 ## Documentation Deployment
 
 To enable automatic documentation deployment to GitHub Pages:

docs/github-workflows-guide.md

@@ -25,6 +25,9 @@ push / PR to main + weekly
 
 ### `CI and Release`
 - 触发：`push` 到 `main`、对 `main` 的 `pull_request`、手动 `workflow_dispatch`
+- 并发：**默认并行**，多次 push 可同时运行（`run_number` 天然唯一，版本不冲突）
+  - 如需串行：Settings → Variables → 设置 `CI_SERIAL=true`（按分支排队）
+  - 如需取消旧 run：设置 `CI_CANCEL_IN_PROGRESS=true`
 - PR 行为：只在 ubuntu 上运行 Build + Test（带 prerelease suffix）
 - main push 行为：全平台矩阵 Build + Test + Pack + Publish + PackageApp → approval → NuGet 推送 + tag + GitHub Release → 文档部署
 - 产物：测试结果、NuGet 包（含 release manifest）、各平台安装包 zip