Add bounded stdin to owner execution

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a06def-6490-7033-8448-2eab2d12ed44

src/sandboxer/extensions/bwrap.py

@@ -184,6 +184,7 @@ class BwrapExtension(SandboxExtension):
         execution_context: dict[str, str],
         timeout_seconds: int,
         max_output_bytes: int,
+        stdin_text: str | None = None,
     ) -> dict[str, object]:
         """Ask the broker already inside bwrap to run an argument-vector command."""
         pid = int(handle.get("pid", "0"))
@@ -197,6 +198,7 @@ class BwrapExtension(SandboxExtension):
             "execution_context": execution_context,
             "timeout_seconds": timeout_seconds,
             "max_output_bytes": max_output_bytes,
+            "stdin_text": stdin_text,
         }
         response_limit = max_output_bytes * 2 + 65_536
         chunks: list[bytes] = []