Fix linting errors across backend and frontend

Backend: auto-fix and format all ruff issues, manually fix B904/B023/
SIM117/B007/E741/F841 errors, suppress B008 (FastAPI Depends) and F821
(SQLAlchemy forward refs) in config. Frontend: allow constant exports,
disable React compiler-specific rules (set-state-in-effect,
preserve-manual-memoization).

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

backend/src/app/api/stats.py

@@ -84,8 +84,12 @@ async def get_stats(session: AsyncSession = Depends(get_session)):
     fainted_count = enc.fainted
     missed_count = enc.missed
 
-    catch_rate = round(caught_count / total_encounters, 4) if total_encounters > 0 else None
-    avg_encounters_per_run = round(total_encounters / total_runs, 1) if total_runs > 0 else None
+    catch_rate = (
+        round(caught_count / total_encounters, 4) if total_encounters > 0 else None
+    )
+    avg_encounters_per_run = (
+        round(total_encounters / total_runs, 1) if total_runs > 0 else None
+    )
 
     # --- Top caught pokemon (top 10) ---
     top_caught_q = await session.execute(
@@ -102,7 +106,9 @@ async def get_stats(session: AsyncSession = Depends(get_session)):
         .limit(10)
     )
     top_caught_pokemon = [
-        PokemonRanking(pokemon_id=r.id, name=r.name, sprite_url=r.sprite_url, count=r.count)
+        PokemonRanking(
+            pokemon_id=r.id, name=r.name, sprite_url=r.sprite_url, count=r.count
+        )
         for r in top_caught_q.all()
     ]
 
@@ -120,7 +126,9 @@ async def get_stats(session: AsyncSession = Depends(get_session)):
         .limit(10)
     )
     top_encountered_pokemon = [
-        PokemonRanking(pokemon_id=r.id, name=r.name, sprite_url=r.sprite_url, count=r.count)
+        PokemonRanking(
+            pokemon_id=r.id, name=r.name, sprite_url=r.sprite_url, count=r.count
+        )
         for r in top_enc_q.all()
     ]
 
@@ -149,8 +157,7 @@ async def get_stats(session: AsyncSession = Depends(get_session)):
         .limit(5)
     )
     top_death_causes = [
-        DeathCause(cause=r.death_cause, count=r.count)
-        for r in death_causes_q.all()
+        DeathCause(cause=r.death_cause, count=r.count) for r in death_causes_q.all()
     ]
 
     # Average levels
@@ -179,8 +186,7 @@ async def get_stats(session: AsyncSession = Depends(get_session)):
         .order_by(func.count().desc())
     )
     type_distribution = [
-        TypeCount(type=r.type_name, count=r.count)
-        for r in type_q.all()
+        TypeCount(type=r.type_name, count=r.count) for r in type_q.all()
     ]
 
     return StatsResponse(