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/combat/combat.service.ts

@@ -1,6 +1,7 @@
 import { Injectable, BadRequestException } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
+import { EventEmitter2 } from '@nestjs/event-emitter';
 import { Character } from '../character/entities/character.entity';
 import { Monster } from '../monster/monster.entity';
 import { MonsterService } from '../monster/monster.service';
@@ -9,6 +10,7 @@ import { StartCombatDto } from './dto/start-combat.dto';
 import { User } from '../user/user.entity';
 import { ItemService } from '../item/item.service';
 import { MaterialService } from '../material/material.service';
+import { CommunityService } from '../community/community.service';
 import {
   resolveCombat,
   applyXpGain,
@@ -31,6 +33,8 @@ export class CombatService {
     private readonly monsterService: MonsterService,
     private readonly itemService: ItemService,
     private readonly materialService: MaterialService,
+    private readonly communityService: CommunityService,
+    private readonly eventEmitter: EventEmitter2,
   ) {}
 
   async startCombat(dto: StartCombatDto, user: User) {
@@ -126,12 +130,63 @@ export class CombatService {
       character.gold = Math.max(0, character.gold - goldLost);
     }
 
+    // Track total gold earned (for achievements)
+    if (result.winner === 'player') {
+      character.totalGoldEarned = Number(character.totalGoldEarned ?? 0) + result.goldEarned;
+    }
+
     // Sauvegarder l'endurance (lazy reset)
     character.hpCurrent = newHp;
     character.enduranceSaved = newEnduranceSaved;
     character.lastEnduranceTs = new Date();
     await this.characterRepository.save(character);
 
+    // Emit achievement & community events
+    if (result.winner === 'player') {
+      this.eventEmitter.emit('achievement.check', {
+        characterId: character.id,
+        type: 'combat_wins',
+        increment: 1,
+      });
+      this.eventEmitter.emit('achievement.check', {
+        characterId: character.id,
+        type: 'level_reached',
+        increment: 0,
+        absolute: character.level,
+      });
+      this.eventEmitter.emit('achievement.check', {
+        characterId: character.id,
+        type: 'gold_accumulated',
+        increment: 0,
+        absolute: Number(character.totalGoldEarned),
+      });
+      this.eventEmitter.emit('community.contribute', {
+        characterId: character.id,
+        type: 'total_monsters_killed',
+        increment: 1,
+      });
+      this.eventEmitter.emit('community.contribute', {
+        characterId: character.id,
+        type: 'total_gold_earned',
+        increment: result.goldEarned,
+      });
+    }
+
+    // Apply XP boost from community
+    if (result.winner === 'player') {
+      const xpBoost = await this.communityService.getActiveMultiplier('xp_boost');
+      if (xpBoost > 1.0) {
+        const bonusXp = Math.floor(result.xpEarned * (xpBoost - 1));
+        if (bonusXp > 0) {
+          const boosted = applyXpGain(character.level, character.xp, bonusXp);
+          character.xp = boosted.newXp;
+          character.level = boosted.newLevel;
+          character.statPoints = (character.statPoints ?? 0) + boosted.statPointsGained;
+          await this.characterRepository.save(character);
+        }
+      }
+    }
+
     // Loot matériaux — 40% de chance après victoire si le monstre a un drop_material_id
     let lootMaterial: { name: string; quantity: number } | null = null;
     if (result.winner === 'player' && monster.dropMaterialId && Math.random() < 0.4) {