Fix live CAN feedback with CH0-only asynchronous risk transmission

Send 0x1F6 risk updates through a bounded latest-result worker on CH0 and disable CH1 initialization, reception, transmission and live display. Preserve the four actual-position bytes from 0x391 and recorded-session compatibility.

Include regression coverage, Orin camera/TensorRT/CAN validation, and the verified standalone binary with refreshed checksums.

include/can_bus.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include "can_types.hpp"
 #include <memory>
+#include <string_view>
 
 namespace cms {
 // One lifecycle per instance; only one owner per device index in a process.
@@ -19,6 +20,15 @@ public:
     // Thread-safe on-demand data-frame send; invalid frames throw, SDK failure
     // returns false. Never generates periodic or inference-triggered messages.
     bool send(CanFrame const& frame);
+    // Send one standard 8-byte 0x1F6 frame on CH0. Both nibbles of
+    // data[0] contain 0 for "clear", 1 for every other level (including
+    // unavailable): 0x00 or 0x11. Bytes 1-7 are zero. Returns {CH0 result, false};
+    // the second slot is retained for API compatibility, CH1 is never sent.
+    std::array<bool,2> sendRisk(std::string_view riskLevel);
+    // Nonblocking live-inference path. Keeps at most one pending risk result;
+    // a newer result replaces one waiting behind a slow SDK send. Returns
+    // queue acceptance, not delivery. No timer or retransmission of old risk.
+    bool queueRisk(std::string_view riskLevel);
 private:
     struct Impl;
     std::unique_ptr<Impl> impl_;

include/can_types.hpp

@@ -5,6 +5,7 @@
 #include <vector>
 
 namespace cms {
+inline constexpr unsigned liveCanChannelCount=1; // CH0 only; CH1 is not used.
 struct CanConfig {
     bool enabled{true};
     int device_index{0};
@@ -22,6 +23,7 @@ struct CanDoorSignals {
 };
 struct CanSnapshot {
     std::string source{"live"},status{"DISABLED"};
+    // Keep two slots for existing recorded sessions; live CH1 stays unset.
     std::array<CanDoorSignals,2> channels;
     std::uint64_t received{},transmitted{},transmit_errors{},receive_errors{};
 };