Patch Panel Runtime Fixture

two-box-sync.json is a local runtime smoke fixture for hwlab-patch-panel. It starts two hwlab-box-simu services and applies one active wiring config to the patch panel.

The smoke proves that patch-panel-owned propagation can synchronize:

res_boxsimu_runtime_1:DO1 -> res_boxsimu_runtime_2:DI1
res_boxsimu_runtime_1:AO1 -> res_boxsimu_runtime_2:AI1
res_boxsimu_runtime_1:FREQ_OUT1 -> res_boxsimu_runtime_2:FREQ_IN1

The local smoke does not deploy DEV/PROD services, connect to real hardware, or write audit rows.