fix(tools): make code result cards authoritative

examples/acp-agent/tests/snapshots/code-mode-turn/input.json

@@ -2,6 +2,6 @@
   "steps": [
     { "op": "initialize" },
     { "op": "newSession" },
-    { "op": "prompt", "text": "Using ONE run_code program: call the bash tool twice — exactly `echo CODE_ONE` then exactly `echo CODE_TWO` — and return the two outputs joined with a plus sign. Then reply with that joined string only and stop." }
+    { "op": "prompt", "text": "Using ONE run_code program: call the bash tool twice — exactly `echo CODE_ONE` then exactly `echo CODE_TWO`. Inside that same program, console.log exactly `captured output`, then return the two outputs joined with a plus sign. Reply with that joined string only and stop." }
   ]
 }