feat(city): add humanoid worker robots as city agents

Seed five worker robot agents (TR-01 to TR-05) with Portuguese
system prompts and active status. Extend the 3D humanoid renderer
with metallic materials, glowing visor, antenna beacon, and chest
status light for the worker_robot type. Add feature tests covering
payload serialization and city bounds validation.

database/seeders/CityWorldSeeder.php

@@ -67,6 +67,37 @@ class CityWorldSeeder extends Seeder
             ],
         );
 
+        // --- Humanoid worker robots (walk the city like pedestrians) ---
+        $robotSpawns = [
+            ['Robô TR-01', 12, -16],
+            ['Robô TR-02', -18, 10],
+            ['Robô TR-03', 100, -14],
+            ['Robô TR-04', -60, 14],
+            ['Robô TR-05', 60, 26],
+        ];
+        $robotModel = (string) config('ai.default_model');
+        if (! in_array($robotModel, config('ai.allowed_models', []), true)) {
+            $robotModel = 'deepseek/deepseek-v4-flash-0731';
+        }
+        foreach ($robotSpawns as [$name, $rx, $rz]) {
+            AiAgent::updateOrCreate(
+                ['name' => $name],
+                [
+                    'type' => 'worker_robot',
+                    'model' => $robotModel,
+                    'system_prompt' => 'Você é '.$name.', um robô humanoide trabalhador da cidade '
+                        .'virtual City10. Você circula pelas ruas transportando materiais e ajudando '
+                        .'nas lojas. Fale de forma curta, educada e um pouco robótica, sempre em '
+                        .'português, sem inventar dados pessoais de usuários.',
+                    'current_goal' => 'Circular entre as lojas auxiliando nas tarefas do dia',
+                    'status' => 'active',
+                    'pos_x' => $rx,
+                    'pos_y' => 0,
+                    'pos_z' => $rz,
+                ],
+            );
+        }
+
         $bakery = Store::where('type', 'bakery')->orderBy('id')->first();
         $market = Store::where('type', 'market')->orderBy('id')->first();