chore: tighten scheduling review coverage

tests/wf_server/test_cli.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import json
 
+import pytest
 from typer.testing import CliRunner
 
 from wf_server.cli import app
@@ -583,6 +584,10 @@ def test_rpc_server_cli_enable_scheduler_rejects_mcp_backed_server(
         "wf_server.cli.build_workflow_server_from_legacy_mcp_config",
         fake_build_mcp_server,
     )
+    monkeypatch.setattr(
+        "wf_server.cli.uvicorn.run",
+        lambda *args, **kwargs: pytest.fail("server must not start"),
+    )
 
     result = CliRunner().invoke(
         app,
@@ -638,6 +643,10 @@ def test_rpc_server_cli_config_mcp_sources_reject_scheduler(
         fake_build_server,
     )
     monkeypatch.setattr("wf_server.cli.create_rpc_app", fake_create_rpc_app)
+    monkeypatch.setattr(
+        "wf_server.cli.uvicorn.run",
+        lambda *args, **kwargs: pytest.fail("server must not start"),
+    )
 
     result = CliRunner().invoke(app, ["--config", str(config_path)])