Refactor: rename SimDUT, restructure DUT simulation and test flow

conftest.py

@@ -0,0 +1,25 @@
+import pytest
+from src.instruments.real_dut import RealDUT
+from src.instruments.simulated_dut import SimulatedDUT
+from src.instruments.power_supply import PowerSupply
+from src.interfaces.dummy import DummyBackend
+
+def pytest_addoption(parser):
+    parser.addoption("--sim", action="store_true", help="Use simulation mode")
+
+@pytest.fixture
+def sim_mode(request):
+    return request.config.getoption("--sim")
+
+@pytest.fixture
+def dut(sim_mode):
+    if sim_mode:
+        return SimulatedDUT()
+    return RealDUT()
+
+@pytest.fixture
+def power_supply(sim_mode):
+    if sim_mode:
+        return PowerSupply(DummyBackend())
+    # TODO: Replace with real SCPI interface when ready
+    raise NotImplementedError("Real power supply interface not yet implemented")