Refactor: rename SimDUT, restructure DUT simulation and test flow

docs/simulation.rst

@@ -0,0 +1,23 @@
+Simulation Mode
+===============
+
+The simulation backend allows you to test framework logic without connecting real hardware.
+
+How It Works
+------------
+
+Fixtures like `dut` use mock classes defined in `src/instruments/dut_controller.py`.
+
+Example Methods:
+- `get_version()`
+- `read_temperature()`
+- `set_output_enabled()`
+
+Extending Sim Mode
+------------------
+
+You can expand simulation by:
+- Creating additional dummy instruments
+- Returning randomized or patterned values
+- Adding logs to mimic hardware responses
+