Add genlocke leg progression with advance endpoint and run context

When a run belonging to a genlocke is completed or failed, the genlocke
status updates accordingly. The run detail API now includes genlocke
context (leg order, total legs, genlocke name). A new advance endpoint
creates the next leg's run, and the frontend shows genlocke-aware UI
including a "Leg X of Y" banner, advance button, and contextual
messaging in the end-run modal.

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

frontend/src/types/game.ts

@@ -93,9 +93,18 @@ export interface NuzlockeRun {
   completedAt: string | null
 }
 
+export interface RunGenlockeContext {
+  genlockeId: number
+  genlockeName: string
+  legOrder: number
+  totalLegs: number
+  isFinalLeg: boolean
+}
+
 export interface RunDetail extends NuzlockeRun {
   game: Game
   encounters: EncounterDetail[]
+  genlocke: RunGenlockeContext | null
 }
 
 export interface EncounterDetail extends Encounter {