docs: clarify source build prerequisite

docs/development.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/development.md
-development.md: d5bd18f83f6f2f8fd3d507ec133eea4d4e06abef
-development.zh.md: 0725cfaad74ec2aa3e52f6523a1dbdbdd9da8a39
+development.md: 8d79756c50f82a840d412f52ee980cb0b505f6f1
+development.zh.md: 285bc0309212694d11077fa590edd199b895fe10

docs/development.md

@@ -126,6 +126,12 @@ The root [contributor instructions](../AGENTS.md#commands) summarize common comm
 
 ### Demos
 
+Run the repository build separately before using these source-checkout demos:
+
+```sh
+pnpm run build
+```
+
 The one-shot Headless coding agent needs `DEEPSEEK_API_KEY` in the environment or repo-root `.env`:
 
 ```sh

docs/development.zh.md

@@ -126,6 +126,12 @@ keyless [CI 工作流](../.github/workflows/ci.yml) 将独立门禁分组到若
 
 ### 演示
 
+从源码 checkout 运行这些演示前，请单独执行仓库构建：
+
+```sh
+pnpm run build
+```
+
 单次运行的 Headless coding agent 需要环境变量或仓库根目录 `.env` 中的 `DEEPSEEK_API_KEY`：
 
 ```sh