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>

backend/src/app/schemas/run.py

@@ -27,6 +27,15 @@ class RunResponse(CamelModel):
     completed_at: datetime | None
 
 
+class RunGenlockeContext(CamelModel):
+    genlocke_id: int
+    genlocke_name: str
+    leg_order: int
+    total_legs: int
+    is_final_leg: bool
+
+
 class RunDetailResponse(RunResponse):
     game: GameResponse
     encounters: list[EncounterDetailResponse] = []
+    genlocke: RunGenlockeContext | None = None