Give controllers their own icons instead of the robot icon

The controller subcomponents reused dyad://DyadBotComponents/PlanarDyadBot.svg,
which depicts the plant rather than a controller. Add dedicated step-response
icons under assets/ and point each controller at its own:

- continuous controllers show a smooth step response
- discrete controllers show a sampled staircase plus a clock glyph
- the type is labelled (angle / cascade / cascade + ff); cascade icons show
  nested inner+outer loop responses and the +ff variants add a feed-forward arrow

The top-level *DyadBot models keep the PlanarDyadBot icon.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FxiqD9h4podoj5e4tpLeGk

Author: baggepinnen

assets/AngleController.svg

@@ -73,7 +73,7 @@ relations
   connect(torque_ff, angle_controller.u_ff) {^id20}
   connect(gain2.y, pos_controller.u_ff) {^id21}
 metadata {
-  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/PlanarDyadBot.svg"}},
+  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/CascadeFFController.svg"}},
   "_links": {
     "angle_measurement": {
       "Dyad": {
@@ -198,7 +198,7 @@ relations
   connect(gain.y, zoh.u) {^id31}
   connect(zoh.y, torque) {^id32}
 metadata {
-  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/PlanarDyadBot.svg"}},
+  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/DiscreteCascadeFFController.svg"}},
   "_links": {
     "angle_measurement": {
       "Dyad": {"placement": {"diagram": {"x1": 320, "y1": 640, "x2": 420, "y2": 740}}}

assets/CascadeController.svg

@@ -34,7 +34,7 @@ relations
   connect(constant_ff.y, angle_controller.u_ff) {^id10}
   connect(ref.y, angle_controller.u_s) {^id11}
 metadata {
-  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/PlanarDyadBot.svg"}},
+  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/AngleController.svg"}},
   "_links": {
     "measurement": {
       "Dyad": {"placement": {"diagram": {"x1": -100, "y1": 450, "x2": 0, "y2": 550}}}
@@ -104,7 +104,7 @@ relations
   connect(angle_controller.y, zoh.u) {^id13}
   connect(zoh.y, gain.u) {^id14}
 metadata {
-  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/PlanarDyadBot.svg"}},
+  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/DiscreteAngleController.svg"}},
   "_links": {
     "measurement": {
       "Dyad": {"placement": {"diagram": {"x1": -100, "y1": 450, "x2": 0, "y2": 550}}}
@@ -358,7 +358,7 @@ relations
   connect(constant2.y, angle_controller.u_ff) {^id18}
   connect(pos_reference, pos_controller.u_s) {^id19}
 metadata {
-  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/PlanarDyadBot.svg"}},
+  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/CascadeController.svg"}},
   "_links": {
     "angle_measurement": {
       "Dyad": {"placement": {"diagram": {"x1": 320, "y1": 640, "x2": 420, "y2": 740}}}
@@ -481,7 +481,7 @@ relations
   connect(gain.y, zoh.u) {^id23}
   connect(zoh.y, torque) {^id24}
 metadata {
-  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/PlanarDyadBot.svg"}},
+  "Dyad": {"icons": {"default": "dyad://DyadBotComponents/DiscreteCascadeController.svg"}},
   "_links": {
     "angle_measurement": {
       "Dyad": {"placement": {"diagram": {"x1": 320, "y1": 640, "x2": 420, "y2": 740}}}

assets/CascadeFFController.svg

@@ -130,9 +130,9 @@ controller runs once per clock tick on a `PeriodicClock` with period `Ts`, and a
   push!(__eqs, connect(measurement, sampler.u))
   push!(__eqs, connect(sampler.y, angle_controller.u_m, clock.y))
   push!(__eqs, connect(ref.y, angle_controller.u_s))
+  push!(__eqs, connect(gain.y, torque))
   push!(__eqs, connect(angle_controller.y, zoh.u))
   push!(__eqs, connect(zoh.y, gain.u))
-  push!(__eqs, connect(gain.y, torque))
 
   # Return completely constructed System
   return System(__eqs, t, __vars, __params; systems=__systems, initial_conditions=__initial_conditions, guesses=__guesses, name, initialization_eqs=__initialization_eqs, bindings=__bindings, assertions=__assertions)