feat(city): add city landmarks, stores, luminous signs, and ATC echo guard

Add university and fire station civic buildings plus 7 new store types,
each with facade and luminous blade signs. Extend landmark material
colors and sign accents. Fix ATC dispatch to reject prompt-echoing AI
responses via heuristic guard. Add CityPlacesTest for collision and
roadway avoidance, and extend AirportTest and SignLabelsTest.

tests/Feature/AirportTest.php

@@ -231,4 +231,29 @@ class AirportTest extends TestCase
         $this->assertSame('xiaomi/mimo-v2.6-flash', $models[2]);
         $this->assertSame('xiaomi/mimo-v2.6-flash', config('ai.fallback_model'));
     }
+
+    /**
+     * A model that echoes the prompt instead of speaking as the tower is
+     * rejected and the chain falls through to the next model.
+     */
+    public function test_dispatch_rejects_prompt_echo_replies(): void
+    {
+        config(['ai.openrouter.api_key' => 'test-key']);
+
+        Http::fake([
+            'openrouter.ai/*' => Http::sequence()
+                ->push(['choices' => [['message' => ['content' => 'The user wants a single short sentence in Portuguese, ATC style, authorizing takeoff of flight C10-138 (Pampa Air) on runway 36. Must respond only with the sentence, no quotes.']]]], 200)
+                ->push(['choices' => [['message' => ['content' => 'C10-138, Pampa Air, autorizado para decolagem na pista 36.']]]], 200),
+        ]);
+
+        $this->postJson('/city/airport/dispatch')
+            ->assertStatus(202)
+            ->assertJsonPath('accepted', true);
+
+        $clearance = cache()->get('airport.clearance');
+        $this->assertNotNull($clearance);
+        $this->assertSame('model', $clearance['source']);
+        $this->assertSame('C10-138, Pampa Air, autorizado para decolagem na pista 36.', $clearance['text']);
+        Http::assertSentCount(2);
+    }
 }