fix: harden subprocess output decoding across lessons

s02_tool_use/code.py

@@ -56,8 +56,8 @@ def run_bash(command: str) -> str:
         return "Error: Dangerous command blocked"
     try:
         r = subprocess.run(command, shell=True, cwd=WORKDIR,
-                           capture_output=True, text=True,
-                           encoding="utf-8", errors="replace", timeout=120)
+                           capture_output=True, text=True, errors="replace",
+                           timeout=120)
         out = (r.stdout + r.stderr).strip()
         return out[:50000] if out else "(no output)"
     except subprocess.TimeoutExpired: