fix: handle todo_write string inputs for issue 340

Co-authored-by: gui-yue <yuemeng.gui@gmail.com>

s07_skill_loading/code.py

@@ -26,7 +26,7 @@ Run: python s07_skill_loading/code.py
 Needs: pip install anthropic python-dotenv pyyaml + ANTHROPIC_API_KEY in .env
 """
 
-import os, subprocess
+import ast, json, os, subprocess
 from pathlib import Path
 import yaml
 
@@ -168,13 +168,31 @@ def run_glob(pattern: str) -> str:
     except Exception as e:
         return f"Error: {e}"
 
+def _normalize_todos(todos):
+    if isinstance(todos, str):
+        try:
+            todos = json.loads(todos)
+        except json.JSONDecodeError:
+            try:
+                todos = ast.literal_eval(todos)
+            except (SyntaxError, ValueError):
+                return None, "Error: todos must be a list or JSON array string"
+    if not isinstance(todos, list):
+        return None, "Error: todos must be a list"
+    for i, t in enumerate(todos):
+        if not isinstance(t, dict):
+            return None, f"Error: todos[{i}] must be an object"
+        if "content" not in t or "status" not in t:
+            return None, f"Error: todos[{i}] missing 'content' or 'status'"
+        if t["status"] not in ("pending", "in_progress", "completed"):
+            return None, f"Error: todos[{i}] has invalid status '{t['status']}'"
+    return todos, None
+
 def run_todo_write(todos: list) -> str:
     global CURRENT_TODOS
-    for i, t in enumerate(todos):
-        if "content" not in t or "status" not in t:
-            return f"Error: todos[{i}] missing 'content' or 'status'"
-        if t["status"] not in ("pending", "in_progress", "completed"):
-            return f"Error: todos[{i}] has invalid status '{t['status']}'"
+    todos, error = _normalize_todos(todos)
+    if error:
+        return error
     CURRENT_TODOS = todos
     lines = ["\n\033[33m## Current Tasks\033[0m"]
     for t in CURRENT_TODOS: