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.

app/Http/Controllers/Web/CityViewerController.php

@@ -365,13 +365,49 @@ class CityViewerController extends Controller
             }
 
             if (is_string($text) && trim($text) !== '') {
-                return mb_substr(trim($text), 0, 240);
+                $text = mb_substr(trim($text), 0, 240);
+                if (self::looksLikeClearance($text, $flight)) {
+                    return $text;
+                }
+                // Model echoed the instruction instead of the clearance:
+                // reject and continue down the chain (next model or the
+                // deterministic fallback in the caller).
+                Log::warning('ATC clearance rejected (not a clearance)', ['model' => $model]);
             }
         }
 
         return null;
     }
 
+    /**
+     * Heuristic guard: a clearance is short, speech-like and about the
+     * requested flight — never a restatement of the prompt itself.
+     *
+     * @param  array{number: string, airline: string, runway: string}  $flight
+     */
+    private static function looksLikeClearance(string $text, array $flight): bool
+    {
+        $lower = mb_strtolower($text);
+
+        $promptMeta = [
+            'the user wants',
+            'respond only',
+            'no quotes',
+            'atc style',
+            'short sentence',
+            'for example',
+            'instructions',
+        ];
+        foreach ($promptMeta as $needle) {
+            if (str_contains($lower, $needle)) {
+                return false;
+            }
+        }
+
+        return str_contains($text, $flight['number'])
+            || preg_match('/autoriz|pista|runway|cleared|descolagem|decolag/iu', $text) === 1;
+    }
+
     /**
      * Resolve the city from the query string or the active default.
      */