Fix run deletion crash and transfer modal initialization error

Run deletion now properly cleans up boss_results, genlocke_transfers,
and genlocke_leg references before deleting the run. Also fix
showTransferModal being referenced before initialization in
RunEncounters by moving its useState declaration above useLegSurvivors.

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

backend/src/app/api/runs.py

@@ -6,9 +6,11 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import joinedload, selectinload
 
 from app.core.database import get_session
+from app.models.boss_result import BossResult
 from app.models.encounter import Encounter
 from app.models.game import Game
 from app.models.genlocke import Genlocke, GenlockeLeg
+from app.models.genlocke_transfer import GenlockeTransfer
 from app.models.nuzlocke_run import NuzlockeRun
 from app.schemas.run import RunCreate, RunDetailResponse, RunGenlockeContext, RunResponse, RunUpdate
 
@@ -198,13 +200,42 @@ async def delete_run(
     if run is None:
         raise HTTPException(status_code=404, detail="Run not found")
 
-    # Delete associated encounters first
+    # Delete associated boss results first
+    boss_results = await session.execute(
+        select(BossResult).where(BossResult.run_id == run_id)
+    )
+    for br in boss_results.scalars():
+        await session.delete(br)
+
+    # Delete genlocke transfers referencing this run's encounters
+    encounter_ids_result = await session.execute(
+        select(Encounter.id).where(Encounter.run_id == run_id)
+    )
+    encounter_ids = [row[0] for row in encounter_ids_result]
+    if encounter_ids:
+        transfers = await session.execute(
+            select(GenlockeTransfer).where(
+                GenlockeTransfer.source_encounter_id.in_(encounter_ids)
+                | GenlockeTransfer.target_encounter_id.in_(encounter_ids)
+            )
+        )
+        for t in transfers.scalars():
+            await session.delete(t)
+
+    # Delete associated encounters
     encounters = await session.execute(
         select(Encounter).where(Encounter.run_id == run_id)
     )
     for enc in encounters.scalars():
         await session.delete(enc)
 
+    # Unlink from any genlocke leg
+    leg_result = await session.execute(
+        select(GenlockeLeg).where(GenlockeLeg.run_id == run_id)
+    )
+    for leg in leg_result.scalars():
+        leg.run_id = None
+
     await session.delete(run)
     await session.commit()
     return Response(status_code=204)