feat(phase2): Add achievements and replay systems

Achievement System:
- Add Achievement model with condition types (streak, steal, specialist, etc.)
- Add AchievementManager service for tracking and awarding achievements
- Add Pydantic schemas for achievements (AchievementResponse, PlayerStats, etc.)
- Seed 18 achievements from design doc
- Add GET /api/game/achievements endpoint

Replay System:
- Add ReplayManager service for saving/loading game replays
- Add GET /api/replay/{code} and /api/replay/session/{id} endpoints
- Format replays for frontend consumption

Phase 2 tasks completed:
- F2.1: Achievement model and migration
- F2.2: Pydantic schemas
- F2.3: AchievementManager service
- F2.4: ReplayManager service
- F2.5: API endpoints
- F2.6: Seed 18 achievements data

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

backend/app/api/game.py

@@ -1,4 +1,4 @@
-from fastapi import APIRouter, HTTPException
+from fastapi import APIRouter, HTTPException, Depends
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 from datetime import date
@@ -8,6 +8,8 @@ from app.models.base import get_db
 from app.models.question import Question
 from app.models.category import Category
 from app.schemas.game import RoomCreate, RoomJoin, GameState
+from app.services.achievement_manager import achievement_manager
+from app.schemas.achievement import AchievementResponse
 
 router = APIRouter()
 
@@ -94,26 +96,8 @@ async def get_question(question_id: int):
     }
 
 
-@router.get("/achievements")
-async def get_achievements():
-    """Get list of all available achievements."""
-    return [
-        {"id": 1, "name": "Primera Victoria", "description": "Ganar tu primera partida", "icon": "🏆"},
-        {"id": 2, "name": "Racha de 3", "description": "Responder 3 correctas seguidas", "icon": "🔥"},
-        {"id": 3, "name": "Racha de 5", "description": "Responder 5 correctas seguidas", "icon": "🔥🔥"},
-        {"id": 4, "name": "Ladrón Novato", "description": "Primer robo exitoso", "icon": "🦝"},
-        {"id": 5, "name": "Ladrón Maestro", "description": "5 robos exitosos en una partida", "icon": "🦝👑"},
-        {"id": 6, "name": "Especialista Nintendo", "description": "10 correctas en Nintendo", "icon": "🍄"},
-        {"id": 7, "name": "Especialista Xbox", "description": "10 correctas en Xbox", "icon": "🎮"},
-        {"id": 8, "name": "Especialista PlayStation", "description": "10 correctas en PlayStation", "icon": "🎯"},
-        {"id": 9, "name": "Especialista Anime", "description": "10 correctas en Anime", "icon": "⛩️"},
-        {"id": 10, "name": "Especialista Música", "description": "10 correctas en Música", "icon": "🎵"},
-        {"id": 11, "name": "Especialista Películas", "description": "10 correctas en Películas", "icon": "🎬"},
-        {"id": 12, "name": "Especialista Libros", "description": "10 correctas en Libros", "icon": "📚"},
-        {"id": 13, "name": "Especialista Historia", "description": "10 correctas en Historia-Cultura", "icon": "🏛️"},
-        {"id": 14, "name": "Invicto", "description": "Ganar sin fallar ninguna pregunta", "icon": "⭐"},
-        {"id": 15, "name": "Velocista", "description": "Responder correctamente en menos de 3 segundos", "icon": "⚡"},
-        {"id": 16, "name": "Comeback", "description": "Ganar estando 500+ puntos abajo", "icon": "🔄"},
-        {"id": 17, "name": "Dominio Total", "description": "Responder las 5 preguntas de una categoría", "icon": "👑"},
-        {"id": 18, "name": "Arriesgado", "description": "Responder correctamente 3 preguntas de 500 pts", "icon": "🎰"},
-    ]
+@router.get("/achievements", response_model=list[AchievementResponse])
+async def get_achievements(db: AsyncSession = Depends(get_db)):
+    """Obtiene lista de todos los logros disponibles"""
+    achievements = await achievement_manager.get_all_achievements(db)
+    return achievements