fix: harden subprocess output decoding across lessons

skills/agent-builder/references/minimal-agent.py

@@ -70,7 +70,7 @@ def execute_tool(name: str, args: dict) -> str:
         try:
             r = subprocess.run(
                 args["command"], shell=True, cwd=WORKDIR,
-                capture_output=True, text=True, timeout=60
+                capture_output=True, text=True, errors="replace", timeout=60
             )
             return (r.stdout + r.stderr).strip() or "(empty)"
         except subprocess.TimeoutExpired:

skills/agent-builder/references/tool-templates.py

@@ -168,7 +168,7 @@ def run_bash(command: str) -> str:
             shell=True,
             cwd=WORKDIR,
             capture_output=True,
-            text=True,
+            text=True, errors="replace",
             timeout=60
         )
         output = (result.stdout + result.stderr).strip()