feat(city): add pedestrian traffic signals with walk/wait indicators

- Adds 3D pedestrian signal heads at each intersection corner
- Implements pedestrian signal state logic tied to vehicle traffic phases
- Displays localized wait banner when pedestrian signal is red
- Includes test asset for pedestrian signal visualization

lang/en.json

@@ -216,5 +216,6 @@
     "city.exercise_tired": "You are too tired to exercise.",
     "city.exercise_max_health": "Health is already at maximum!",
     "city.exerciseStart": "Starting exercise…",
-    "city.exerciseStop": "Exercise stopped."
+    "city.exerciseStop": "Exercise stopped.",
+    "city.ped_red": "Red pedestrian light — wait for the walk signal."
 }

lang/es.json

@@ -216,5 +216,6 @@
     "city.exercise_tired": "Está demasiado cansado para ejercitarse.",
     "city.exercise_max_health": "¡La salud ya está en el máximo!",
     "city.exerciseStart": "Empezando a ejercitarse…",
-    "city.exerciseStop": "Ejercicio terminado."
+    "city.exerciseStop": "Ejercicio terminado.",
+    "city.ped_red": "Semáforo de peatón en rojo — espere la señal verde."
 }

lang/pt_BR.json

@@ -216,5 +216,6 @@
     "city.exercise_tired": "Você está cansado demais para se exercitar.",
     "city.exercise_max_health": "Saúde já está no máximo!",
     "city.exerciseStart": "Começando a se exercitar…",
-    "city.exerciseStop": "Exercício encerrado."
+    "city.exerciseStop": "Exercício encerrado.",
+    "city.ped_red": "Semáforo de pedestre vermelho — aguarde o sinal verde."
 }