added legacy gpr

docs/operation_modes.md

@@ -18,6 +18,7 @@ run_config_librevna.example.json
 run_config_librevna_multi.example.json
 run_config_compact_m_k209.example.json
 run_config_compact_m_k209_local_mock_switches.example.json
+run_config_simulator.example.json
 ```
 
 ## Common Commands
@@ -47,6 +48,23 @@ The GUI process supervisor starts the correct producer automatically:
 - `compact_m_k209` -> `build/bin/sweep_orchestrator`
 - `librevna_multi` -> `python_app.scripts.multi_device_raw_producer`
 
+## Pure Simulator
+
+Use `run_config_simulator.example.json` to run the full GUI pipeline without
+radar hardware or GPIO. It uses the single-LibreVNA mock producer, mock
+switches, and the synthetic `smoke_cal` / `smoke_ref` preprocessing sets stored
+under `python_app/data`.
+
+Typical local check:
+
+```bash
+cd /path/to/radar_system
+make
+.venv/bin/python -m python_app.gui.main
+```
+
+Then load `run_config_simulator.example.json` in the GUI and press Start.
+
 ## Single LibreVNA
 
 Use this mode when one LibreVNA is connected directly over USB to the machine
@@ -210,4 +228,3 @@ sends one command byte and receives only binary `S11` and `S21` `float32`
 arrays.
 
 Use wired Ethernet. Wi-Fi works for tests but adds jitter.
-