Add owner-mediated bwrap execution boundary

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

src/sandboxer/extensions/base.py

@@ -47,6 +47,23 @@ class SandboxExtension(ABC):
         """Optional post-destroy actual cost in USD."""
         return None
 
+    def supports_execution(self) -> bool:
+        """Whether the owner can run a command inside an established sandbox."""
+        return False
+
+    def execute(
+        self,
+        handle: dict[str, str],
+        command: list[str],
+        *,
+        credential_route_refs: list[str],
+        execution_context: dict[str, str],
+        timeout_seconds: int,
+        max_output_bytes: int,
+    ) -> dict[str, object]:
+        """Run a bounded command through an owner-mediated sandbox boundary."""
+        raise NotImplementedError(f"{type(self).__name__} does not support execution")
+
     def supports_snapshots(self) -> bool:
         """Whether this extension implements checkpoint snapshot/restore."""
         return False
@@ -63,4 +80,4 @@ class SandboxExtension(ABC):
         host: str,
     ) -> dict[str, str]:
         """Provision a new sandbox from a prior checkpoint."""
-        raise NotImplementedError(f"{type(self).__name__} does not support restore")
+        raise NotImplementedError(f"{type(self).__name__} does not support restore")