carControl API cleanup (commaai#33543)

carControl cleanup

cereal/car.capnp

@@ -352,21 +352,21 @@ struct CarControl {
   hudControl @5 :HUDControl;
 
   struct Actuators {
-    # range from 0.0 - 1.0
-    gas @0: Float32;
-    brake @1: Float32;
-    # range from -1.0 - 1.0
-    steer @2: Float32;
-    # value sent over can to the car
-    steerOutputCan @8: Float32;
+    # lateral commands, mutually exclusive
+    steer @2: Float32;  # [0.0, 1.0]
     steeringAngleDeg @3: Float32;
-
     curvature @7: Float32;
 
-    speed @6: Float32; # m/s
-    accel @4: Float32; # m/s^2
+    # longitudinal commands
+    accel @4: Float32;  # m/s^2
     longControlState @5: LongControlState;
 
+    # these are only for logging the actual values sent to the car over CAN
+    gas @0: Float32;   # [0.0, 1.0]
+    brake @1: Float32; # [0.0, 1.0]
+    steerOutputCan @8: Float32;   # value sent over can to the car
+    speed @6: Float32;  # m/s
+
     enum LongControlState @0xe40f3a917d908282{
       off @0;
       pid @1;