docs: translate code comments in Chinese READMEs (s04-s06) (#590)

s04_hooks/README.zh.md

@@ -85,7 +85,7 @@ def trigger_hooks(event: str, *args):
 def context_inject_hook(query: str) -> str | None:
     """Inject current working directory info into every prompt."""
     print(f"\033[90m[HOOK] UserPromptSubmit: working in {WORKDIR}\033[0m")
-    return None   # return None = no modification, let prompt through
+    return None   # return None = 不修改提示词，直接放行
 
 register_hook("UserPromptSubmit", context_inject_hook)
 ```
@@ -139,7 +139,7 @@ def summary_hook(messages: list) -> str | None:
                      for b in (m.get("content") if isinstance(m.get("content"), list) else [])
                      if isinstance(b, dict) and b.get("type") == "tool_result")
     print(f"\033[90m[HOOK] Stop: session used {tool_count} tool calls\033[0m")
-    return None   # return None = allow stop, return string = force continuation
+    return None   # return None = 允许终止, return string = 强制继续
 
 register_hook("Stop", summary_hook)
 ```
@@ -153,7 +153,7 @@ tool_calls = [
 if not tool_calls:
     force = trigger_hooks("Stop", messages)   # ← 退出之前
     if force:
-        # hook returned a message → inject it and continue
+        # hook 返回消息 → 注入消息并继续执行
         messages.append({"role": "user", "content": force})
         continue
     return

s05_todo_write/README.zh.md

@@ -40,14 +40,14 @@ class TodoManager:
         self.items = []
 
     def update(self, todos: list | str) -> str:
-        # Parse and validate before replacing the current list.
+        # 替换当前列表前进行解析与校验
         validated = []
         ...
         self.items = validated
         return self.render()
 
     def render(self) -> str:
-        # [ ] pending, [>] in progress, [x] completed
+        # [ ] 待办, [>] 进行中, [x] 已完成
         ...
 
 

s06_subagent/README.zh.md

@@ -31,7 +31,7 @@ Agent 在修一个 bug。为了追踪调用链，它读取了许多文件；每
 **run_subagent** 创建新的消息列表，运行嵌套循环，并返回最终文本：
 
 ```python
-SUB_TOOLS = list(BASE_TOOLS)  # no task tool
+SUB_TOOLS = list(BASE_TOOLS)  # 不含 task 工具
 
 def run_subagent(prompt: str) -> str:
     messages = [{"role": "user", "content": prompt}]