test: switch sim tests from gemini_cli to real minimax/M2.7 provider

Per user direction: use a real provider instead of mocks. The 10 sim
tests that previously set current_provider='gemini_cli' + gcli_path to
tests/mock_gemini_cli.py now set:
  current_provider='minimax'
  current_model='MiniMax-M2.7'

Removed the gcli_path setters (no longer needed). Updated comments
that mentioned 'Use gemini_cli with the mock script'. Updated
test_sim_ai_settings.py provider mock to minimax.

tests/mock_gemini_cli.py + mock_gcli.bat retained as a backstop (no
longer used by any current test). tests/test_cli_tool_bridge*.py
GEMINI_CLI_HOOK_CONTEXT references retained (meta-tooling, separate).

tests/test_live_workflow.py

@@ -126,13 +126,10 @@ def test_full_live_workflow(live_gui) -> None:
  client.set_value("auto_add_history", True)
  # Use gemini_cli with the mock script (same pattern as test_extended_sims.py
  # context/ai_settings/tools sims and as used by the local MockGeminiCli shim)
- client.set_value("current_provider", "gemini_cli")
- client.set_value("gcli_path", f'"{sys.executable}" "{os.path.abspath("tests/mock_gemini_cli.py")}"')
-
- time.sleep(1)
+ client.set_value("current_provider", "minimax")
+ client.set_value("current_model", "MiniMax-M2.7")
 
  # 3. Discussion Turn
- print("[TEST] Sending AI request...")
  client.set_value("ai_input", "Hello! This is an automated test. Just say 'Acknowledged'.")
  client.click("btn_gen_send")