test(ext-sims): fix execution_sim_live dodge by using gemini_cli mock

The test was previously marked @pytest.mark.skip because it used
current_provider='gemini' (the real Gemini API). With no API key, the
GUI subprocess returns 'ai_status: error' after 3 consecutive errors
and aborts the simulation.

The 3 OTHER live tests in this file (context_sim_live, ai_settings_sim_live,
tools_sim_live) all set current_provider='gemini_cli' and override
gcli_path to point to tests/mock_gemini_cli.py — this REPLACES the real
gemini_cli subprocess with a canned-response mock. They pass.

Removed the skip decorator and applied the same pattern:
- current_provider: gemini_cli (was: gemini)
- gcli_path: tests/mock_gemini_cli.py (was: not set)
- Removed the (unreachable) current_model setting

Verification: tier-3-live_gui PASS in 602s with this test now PASSING
(was: SKIPPED).

tests/test_extended_sims.py

@@ -56,7 +56,6 @@ def test_tools_sim_live(live_gui: Any) -> None:
  time.sleep(2)
  sim.teardown()
 @pytest.mark.integration
-@pytest.mark.skip(reason="Requires real AI provider (gemini API key); 3 consecutive error status aborts the simulation. Pre-existing flake documented in fix_test_failures_20260624. See docs/reports/TRACK_COMPLETION_fix_test_failures_20260624.md VC4 PARTIAL note.")
 def test_execution_sim_live(live_gui: Any) -> None:
  """Run the Execution & Modals simulation against a live GUI."""
  client = ApiHookClient()
@@ -65,8 +64,10 @@ def test_execution_sim_live(live_gui: Any) -> None:
  sim.setup("LiveExecutionSim")
  # Enable manual approval to test modals
  client.set_value('manual_approve', True)
- client.set_value('current_provider', 'gemini')
- client.set_value('current_model', 'gemini-2.5-flash-lite')
+ # Use gemini_cli with the mock script (same pattern as the other 3 sims
+ # in this file: context_sim_live, ai_settings_sim_live, tools_sim_live)
+ client.set_value('current_provider', 'gemini_cli')
+ client.set_value('gcli_path', f'"{sys.executable}" "{os.path.abspath("tests/mock_gemini_cli.py")}"')
  client.set_value('auto_add_history', True)
  sim.run()
  time.sleep(2)