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>

frontend/src/types/game.ts

@@ -1,15 +1,31 @@
+export type GameCategory = 'original' | 'remake' | 'enhanced' | 'sequel' | 'spinoff'
+
 export interface Game {
   id: number
   name: string
   slug: string
   generation: number
   region: string
+  category: GameCategory | null
   boxArtUrl: string | null
   releaseYear: number | null
   color: string | null
   versionGroupId: number | null
 }
 
+export interface GenlockeDefaults {
+  trueGenlocke: string  // game slug
+  normalGenlocke: string  // game slug
+}
+
+export interface Region {
+  name: string
+  generation: number
+  order: number
+  genlockeDefaults: GenlockeDefaults
+  games: Game[]
+}
+
 export interface Route {
   id: number
   name: string