e5d1b3cfc3
- usb_data_interface.v: Add FT601 read FSM (RD_IDLE/OE_ASSERT/READING/ DEASSERT/PROCESS) + cmd_data/valid/opcode/addr/value output ports - radar_system_top.v: Connect cmd_* ports from usb_inst, add toggle CDC for cmd_valid (ft601_clk -> clk_100m), add command decode registers (mode/trigger/cfar_threshold/stream_control), wire host_mode and host_trigger to rx_inst - radar_receiver_final.v: Add host_mode[1:0] and host_trigger input ports, replace hardcoded mode/trigger in radar_mode_controller instance - tb_usb_data_interface.v: Connect cmd_* ports, add host data bus driver, add Test Groups 12 (single command), 13 (multiple commands), 14 (read/write interleave). USB TB now has 55 checks. Regression: 18/18 PASS