Add Pinwheel Clause support for zone-based encounters in route groups

Allows each sub-zone within a route group to have its own independent
encounter when the Pinwheel Clause rule is enabled (default on), instead
of the entire group sharing a single encounter.

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

frontend/src/types/admin.ts

@@ -19,11 +19,13 @@ export interface UpdateGameInput {
 export interface CreateRouteInput {
   name: string
   order: number
+  pinwheelZone?: number | null
 }
 
 export interface UpdateRouteInput {
   name?: string
   order?: number
+  pinwheelZone?: number | null
 }
 
 export interface RouteReorderItem {

frontend/src/types/game.ts

@@ -15,6 +15,7 @@ export interface Route {
   gameId: number
   order: number
   parentRouteId: number | null
+  pinwheelZone: number | null
   encounterMethods: string[]
 }
 

frontend/src/types/rules.ts

@@ -5,6 +5,7 @@ export interface NuzlockeRules {
   nicknameRequired: boolean
   duplicatesClause: boolean
   shinyClause: boolean
+  pinwheelClause: boolean
 
   // Difficulty modifiers
   hardcoreMode: boolean
@@ -19,6 +20,7 @@ export const DEFAULT_RULES: NuzlockeRules = {
   nicknameRequired: true,
   duplicatesClause: true,
   shinyClause: true,
+  pinwheelClause: true,
 
   // Difficulty modifiers - off by default
   hardcoreMode: false,
@@ -70,6 +72,13 @@ export const RULE_DEFINITIONS: RuleDefinition[] = [
       'Shiny Pokémon may always be caught, regardless of whether they are your first encounter.',
     category: 'core',
   },
+  {
+    key: 'pinwheelClause',
+    name: 'Pinwheel Clause',
+    description:
+      'Sub-zones within a location group each get their own encounter instead of sharing one.',
+    category: 'core',
+  },
 
   // Difficulty modifiers
   {