Add game category and region metadata for genlocke presets

Add `category` field (original/remake/enhanced/sequel/spinoff) to the
Game model and tag all 38 games. Create regions.json with generation
mapping, ordering, and genlocke preset defaults per region. Add
GET /games/by-region endpoint returning games grouped by region.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/app/api/games.py

@@ -1,3 +1,6 @@
+import json
+from pathlib import Path
+
 from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy import delete, select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -14,6 +17,7 @@ from app.schemas.game import (
     GameDetailResponse,
     GameResponse,
     GameUpdate,
+    RegionResponse,
     RouteCreate,
     RouteReorderRequest,
     RouteResponse,
@@ -46,6 +50,38 @@ async def list_games(session: AsyncSession = Depends(get_session)):
     return result.scalars().all()
 
 
+@router.get("/by-region", response_model=list[RegionResponse])
+async def list_games_by_region(session: AsyncSession = Depends(get_session)):
+    """Return games grouped by region with generation metadata and genlocke preset defaults."""
+    regions_path = Path(__file__).parent.parent / "seeds" / "data" / "regions.json"
+    with open(regions_path) as f:
+        regions_data = json.load(f)
+
+    result = await session.execute(select(Game).order_by(Game.release_year, Game.name))
+    all_games = result.scalars().all()
+
+    games_by_region: dict[str, list[Game]] = {}
+    for game in all_games:
+        games_by_region.setdefault(game.region, []).append(game)
+
+    response = []
+    for region in regions_data:
+        region_games = games_by_region.get(region["name"], [])
+        defaults = region["genlocke_defaults"]
+        response.append({
+            "name": region["name"],
+            "generation": region["generation"],
+            "order": region["order"],
+            "genlocke_defaults": {
+                "true_genlocke": defaults["true"],
+                "normal_genlocke": defaults["normal"],
+            },
+            "games": region_games,
+        })
+
+    return response
+
+
 @router.get("/{game_id}", response_model=GameDetailResponse)
 async def get_game(game_id: int, session: AsyncSession = Depends(get_session)):
     game = await _get_game_or_404(session, game_id)
@@ -66,6 +102,7 @@ async def get_game(game_id: int, session: AsyncSession = Depends(get_session)):
         "slug": game.slug,
         "generation": game.generation,
         "region": game.region,
+        "category": game.category,
         "box_art_url": game.box_art_url,
         "release_year": game.release_year,
         "color": game.color,