添加轻量 runtime 安装脚本

README.md

@@ -10,6 +10,7 @@ Current state:
 - References: `director-gates.md`, `templates/game-concept.md`
 - Standards: `design-docs.md`
 - Commands: `/brainstorm` wrapper document
+- Scripts: `scripts/install_codex_runtime.py` installs bundled custom agents into a target project
 - Marketplace: `.agents/plugins/marketplace.json`
 - No hooks
 - No rules
@@ -25,6 +26,18 @@ The director agents are pre-defined Codex custom agents stored in:
 Each custom agent is a standalone TOML file with `name`, `description`, and
 `developer_instructions`, matching the Codex subagents documentation.
 
+To install the bundled custom agents into a game project:
+
+```bash
+python3 scripts/install_codex_runtime.py /path/to/game-project
+```
+
+The current installer only writes custom agents to:
+
+```text
+/path/to/game-project/.codex/agents/
+```
+
 The only required plugin manifest is:
 
 ```text