fix: materialize final_players queryset before double-iteration in get_random_player

When no position filters are applied, `final_players` is a lazy Peewee queryset
with `ORDER BY RANDOM() LIMIT n`. Iterating it twice (once to build player_ids,
once for the response loop) executes two separate DB queries with different random
seeds, causing dex_by_player to be built for a different player set than returned,
silently producing empty paperdex for all players.

Add `final_players = list(final_players)` before building player_ids to ensure
both iterations operate on the same materialized result. Also fix pre-existing
syntax error in import statement and minor ruff lint issues in the same file.

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

app/routers_v2/players.py

@@ -12,7 +12,7 @@ from pandas import DataFrame
 from playwright.async_api import async_playwright
 
 from ..card_creation import get_batter_card_data, get_pitcher_card_data
-from ..db_engine import (, DoesNotExist
+from ..db_engine import (
     db,
     Player,
     model_to_dict,
@@ -74,7 +74,6 @@ def normalize_franchise(franchise: str) -> str:
     return FRANCHISE_NORMALIZE.get(titled, titled)
 
 
-
 router = APIRouter(prefix="/api/v2/players", tags=["players"])
 
 
@@ -145,7 +144,7 @@ async def get_players(
 ):
     all_players = Player.select()
     if all_players.count() == 0:
-        raise HTTPException(status_code=404, detail=f"There are no players to filter")
+        raise HTTPException(status_code=404, detail="There are no players to filter")
 
     if name is not None:
         all_players = all_players.where(fn.Lower(Player.p_name) == name.lower())
@@ -477,6 +476,7 @@ async def get_random_player(
         return Response(content=return_val, media_type="text/csv")
 
     else:
+        final_players = list(final_players)
         return_val = {"count": len(final_players), "players": []}
         player_ids = [p.player_id for p in final_players]
         dex_by_player = {}
@@ -684,9 +684,6 @@ async def get_batter_card(
         )
 
     headers = {"Cache-Control": "public, max-age=86400"}
-    filename = (
-        f"{this_player.description} {this_player.p_name} {card_type} {d}-v{variant}"
-    )
     if (
         os.path.isfile(
             f"storage/cards/cardset-{this_player.cardset.id}/{card_type}/{player_id}-{d}-v{variant}.png"