fix: use UTF-8 for text file operations

s05_todo_write/code.py

@@ -66,7 +66,7 @@ def run_bash(command: str) -> str:
 
 def run_read(path: str, limit: int | None = None) -> str:
     try:
-        lines = (WORKDIR / path).resolve().read_text().splitlines()
+        lines = (WORKDIR / path).resolve().read_text(encoding="utf-8").splitlines()
         if limit and limit < len(lines):
             lines = lines[:limit] + [f"... ({len(lines) - limit} more lines)"]
         return "\n".join(lines)
@@ -77,7 +77,7 @@ def run_write(path: str, content: str) -> str:
     try:
         file_path = (WORKDIR / path).resolve()
         file_path.parent.mkdir(parents=True, exist_ok=True)
-        file_path.write_text(content)
+        file_path.write_text(content, encoding="utf-8")
         return f"Wrote {len(content)} bytes to {path}"
     except Exception as e:
         return f"Error: {e}"
@@ -85,10 +85,10 @@ def run_write(path: str, content: str) -> str:
 def run_edit(path: str, old_text: str, new_text: str) -> str:
     try:
         file_path = (WORKDIR / path).resolve()
-        text = file_path.read_text()
+        text = file_path.read_text(encoding="utf-8")
         if old_text not in text:
             return f"Error: text not found in {path}"
-        file_path.write_text(text.replace(old_text, new_text, 1))
+        file_path.write_text(text.replace(old_text, new_text, 1), encoding="utf-8")
         return f"Edited {path}"
     except Exception as e:
         return f"Error: {e}"