Add owner-mediated bwrap execution boundary

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

tests/test_reachability.py

@@ -75,4 +75,30 @@ def test_build_reachability_report() -> None:
     report = build_reachability_report(status)
     assert report["sandbox_id"] == "abc12345"
     assert report["ssh_one_liner"] is not None
-    assert "ops_bridge" in report
+    assert "ops_bridge" in report
+
+
+def test_bwrap_report_points_to_owner_execution_not_nsenter() -> None:
+    now = datetime.now(UTC)
+    status = SandboxStatus(
+        sandbox_id="bwrap123",
+        profile_id="profile.bwrap-local",
+        extension_id="ext.bwrap",
+        state=SandboxState.READY,
+        consumer=Consumer(actor=ActorType.AGT, project="glas-harness", run_id="run-1"),
+        host="localhost",
+        reachability=Reachability(
+            host="localhost",
+            endpoint="pid:42",
+            pid="42",
+            workspace_dir="/tmp/sandboxer-bwrap/bwrap123",
+        ),
+        created_at=now,
+        updated_at=now,
+    )
+
+    report = build_reachability_report(status)
+
+    assert report["execution"]["mode"] == "owner-mediated"
+    assert "nsenter" not in str(report)
+    assert "local_exec_hint" not in report