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/halloffame/hall-of-fame.entity.ts

@@ -0,0 +1,33 @@
+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  ManyToOne,
+  JoinColumn,
+} from 'typeorm';
+import { Character } from '../character/entities/character.entity';
+
+@Entity('hall_of_fame')
+export class HallOfFame {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column({ name: 'character_id' })
+  characterId: string;
+
+  @ManyToOne(() => Character)
+  @JoinColumn({ name: 'character_id' })
+  character: Character;
+
+  @Column({ length: 7 })
+  period: string; // 'YYYY-MM'
+
+  @Column()
+  rank: number;
+
+  @Column({ name: 'contribution_total', type: 'bigint' })
+  contributionTotal: number;
+
+  @Column({ length: 50 })
+  badge: string; // 'top1_april_2026'
+}