✨ feat(epic-4): chemins narratifs, easter eggs, challenge et contact

Epic 4: Chemins Narratifs, Challenge & Contact

Stories implementees:
- 4.1: Composant ChoiceCards pour choix narratifs binaires
- 4.2: Sequence d'intro narrative avec Le Bug
- 4.3: Chemins narratifs differencies avec useNarrativePath
- 4.4: Table easter_eggs et systeme de detection (API + composable)
- 4.5: Easter eggs UI (popup, notification, collection)
- 4.6: Page challenge avec puzzle de code
- 4.7: Page revelation "Monde de Code"
- 4.8: Page contact avec formulaire et stats

Fichiers crees:
- Frontend: ChoiceCards, IntroSequence, ZoneEndChoice, EasterEggPopup,
  CodePuzzle, ChallengeSuccess, CodeWorld, et pages intro/challenge/revelation
- API: EasterEggController, Model, Migration, Seeder

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

api/app/Models/EasterEgg.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Model;
+
+class EasterEgg extends Model
+{
+    protected $fillable = [
+        'slug',
+        'location',
+        'trigger_type',
+        'reward_type',
+        'reward_key',
+        'difficulty',
+        'is_active',
+    ];
+
+    protected $casts = [
+        'difficulty' => 'integer',
+        'is_active' => 'boolean',
+    ];
+
+    public function scopeActive(Builder $query): Builder
+    {
+        return $query->where('is_active', true);
+    }
+
+    public function scopeByLocation(Builder $query, string $location): Builder
+    {
+        return $query->where('location', $location);
+    }
+
+    public function getReward(string $lang = 'fr'): ?string
+    {
+        return Translation::getTranslation($this->reward_key, $lang);
+    }
+}