Implement Retire HoF (Gauntlet) rule enforcement for genlockes

When retireHoF is enabled, surviving HoF Pokemon and their evolutionary
families are retired at leg advancement and treated as duplicates in all
subsequent legs — both in the encounter modal and bulk randomize.

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

backend/src/app/api/runs.py

@@ -78,12 +78,29 @@ async def get_run(run_id: int, session: AsyncSession = Depends(get_session)):
             .where(GenlockeLeg.genlocke_id == leg.genlocke_id)
         )
         total_legs = total_legs_result.scalar_one()
+
+        # Aggregate retired Pokemon IDs from prior legs (retireHoF rule)
+        retired_pokemon_ids: list[int] = []
+        if leg.genlocke.genlocke_rules.get("retireHoF", False) and leg.leg_order > 1:
+            prior_result = await session.execute(
+                select(GenlockeLeg.retired_pokemon_ids).where(
+                    GenlockeLeg.genlocke_id == leg.genlocke_id,
+                    GenlockeLeg.leg_order < leg.leg_order,
+                    GenlockeLeg.retired_pokemon_ids.isnot(None),
+                )
+            )
+            cumulative: set[int] = set()
+            for (ids,) in prior_result:
+                cumulative.update(ids)
+            retired_pokemon_ids = sorted(cumulative)
+
         genlocke_context = RunGenlockeContext(
             genlocke_id=leg.genlocke_id,
             genlocke_name=leg.genlocke.name,
             leg_order=leg.leg_order,
             total_legs=total_legs,
             is_final_leg=leg.leg_order == total_legs,
+            retired_pokemon_ids=retired_pokemon_ids,
         )
 
     response = RunDetailResponse.model_validate(run)