feat: synchronize CH1 vehicle control and feedback

src/cognitive_agent/infrastructure/can/hardware.py

@@ -577,8 +577,19 @@ class VehicleCanSettings:
             and (not self.approval_required or self.approval_token)
             and self.adapter_configured
             and self.timing_is_verified
+            and self.channel_is_allowed
         )
 
+    @property
+    def required_channel(self) -> int:
+        """Physical body-CAN channel selected by the fail-closed bench policy."""
+
+        return _env_int("COGNITIVE_AGENT_VEHICLE_CAN_REQUIRED_CHANNEL", 1)
+
+    @property
+    def channel_is_allowed(self) -> bool:
+        return self.channel == self.required_channel == 1
+
     @property
     def timing_is_verified(self) -> bool:
         return (
@@ -610,8 +621,12 @@ class VehicleCanSettings:
             raise HardwareSafetyError(
                 "vehicle CAN FD currently requires the zlgcan multi-channel backend"
             )
-        if self.channel < 0:
-            raise HardwareSafetyError("vehicle CAN channel cannot be negative")
+        if not self.channel_is_allowed:
+            raise HardwareSafetyError(
+                "CH1 driver/body-CAN policy requires "
+                "COGNITIVE_AGENT_VEHICLE_CAN_CHANNEL=1 and "
+                "COGNITIVE_AGENT_VEHICLE_CAN_REQUIRED_CHANNEL=1; CH0 is forbidden"
+            )
         if not self.timing_is_verified:
             raise HardwareSafetyError(
                 "vehicle CAN timing must remain ISO CAN FD 500 kbit/s / 2 Mbit/s at 80% sample point"
@@ -649,6 +664,10 @@ class VehicleCanSettings:
             "backend": self.backend,
             "platform": "t2g_cabin_bench",
             "channel": self.channel,
+            "required_channel": self.required_channel,
+            "channel_is_allowed": self.channel_is_allowed,
+            "target_policy": "ch1_body_can_driver_only",
+            "forbidden_paths": ["ch0", "t2g_seat_bench", "passenger", "front_right"],
             "mode": 0,
             "work_mode": "normal",
             "can_fd_standard": "ISO",