ci: target production runner by unique label

.gitea/workflows/ci.yml

@@ -4,7 +4,7 @@ on:
   pull_request:
 jobs:
   test:
-    runs-on: minecraft-and-affine-server
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - name: Check and test in Node 22

.gitea/workflows/deploy.yml

@@ -3,7 +3,8 @@ on:
   workflow_dispatch:
 jobs:
   deploy:
-    runs-on: minecraft-and-affine-server
+    # This unique host label prevents production from landing on another global runner.
+    runs-on: coffeechat-production
     concurrency: coffeechat-production
     steps:
       - uses: actions/checkout@v4

docs/deployment.md

@@ -2,7 +2,7 @@
 
 ## 1. 主机准备
 
-`minecraft-and-affine-server` Gitea Runner 需要可执行 Docker Compose，并且 Runner 服务账号必须能读取 `/opt/coffeechat/.env`。建议将该文件权限限制为该账号可读：
+`minecraft-and-affine-server` Gitea Runner 需要可执行 Docker Compose，并注册唯一的 `coffeechat-production:host` 标签；部署工作流只匹配该标签，不会被其他全局 Runner 接走。Runner 服务账号必须能读取 `/opt/coffeechat/.env`，建议将该文件权限限制为该账号可读：
 
 ```dotenv
 POSTGRES_PASSWORD=随机数据库密码