fix: use UTF-8 for text file operations

s11_background_tasks/code.py

@@ -124,7 +124,7 @@ def run_bash(command: str, run_in_background: bool = False) -> str:
 def run_read(path: str, limit: int | None = None) -> str:
     try:
         file_path = (WORKDIR / path).resolve()
-        lines = file_path.read_text().splitlines()
+        lines = file_path.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)
@@ -136,7 +136,7 @@ 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 error:
         return f"Error: {error}"
@@ -145,10 +145,10 @@ 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 error:
         return f"Error: {error}"