feat(sprint4): achievements, community goals, hall of fame, profile

4 modules: achievement (15 succès, 5 catégories, 3 paliers), community
(objectifs collectifs + boosts globaux), halloffame (classement mensuel),
profile (titre actif + badges + % progression).

Event-driven: combat/forge/craft émettent des events via @nestjs/event-emitter.
Character entity: +activeTitle, +totalGoldEarned.
Seeds: 15 achievements + 3 community goals.

src/character/entities/character.entity.ts

@@ -71,6 +71,13 @@ export class Character {
   @Column({ name: 'stat_points', default: 0 })
   statPoints: number;
 
+  // Sprint 4 — Profil enrichi
+  @Column({ name: 'active_title', length: 100, nullable: true })
+  activeTitle: string | null;
+
+  @Column({ name: 'total_gold_earned', type: 'bigint', default: 0 })
+  totalGoldEarned: number;
+
   @CreateDateColumn({ name: 'created_at' })
   createdAt: Date;