odstranenie priemernej dlzky hry zo statistik

api/stats.py

@@ -240,14 +240,6 @@ async def get_daily_stats(logged_in_only: bool = False) -> dict:
             )
         ).one()
 
-        avg_duration = (
-            await session.execute(
-                select(func.avg(func.extract("epoch", Game.ended_at - Game.created_at))).where(
-                    Game.ended_at.is_not(None)
-                )
-            )
-        ).scalar()
-
         # Nedokoncena registracia = kod nebol nikdy potvrdeny (SQL obdoba
         # api/auth._is_unconfirmed). "Hraci celkom" pocita len potvrdene ucty,
         # nedokoncene sa vykazuju osobitne.
@@ -338,7 +330,6 @@ async def get_daily_stats(logged_in_only: bool = False) -> dict:
         "players_per_day": {str(r.day): r.n for r in player_rows},
         "finished_bot_games": finished_bot_games,
         "finished_human_games": finished_human_games,
-        "avg_game_duration_minutes": (float(avg_duration) / 60) if avg_duration else None,
         "total_players": total_players,
         "unconfirmed_players": unconfirmed_players,
         "peak_hours": {int(r.h): r.n for r in peak_hours},

frontend/src/pages/admin/AdminStats.tsx

@@ -19,7 +19,6 @@ interface DailyStats {
   players_per_day: Record<string, number>;
   finished_bot_games: number;
   finished_human_games: number;
-  avg_game_duration_minutes: number | null;
   total_players: number;
   unconfirmed_players: number;
   peak_hours: Record<string, number>;
@@ -159,10 +158,6 @@ export default function AdminStats() {
         <SummaryCard label="Nedokončené registrácie" value={String(data.unconfirmed_players)} />
         <SummaryCard label="Dokončené hry s ľuďmi" value={String(data.finished_human_games)} />
         <SummaryCard label="Dokončené hry s botmi" value={String(data.finished_bot_games)} />
-        <SummaryCard
-          label="Priem. dĺžka hry"
-          value={data.avg_game_duration_minutes != null ? `${Math.round(data.avg_game_duration_minutes)} min` : '—'}
-        />
       </div>
 
       <div className={`grid gap-4 ${desktop ? 'grid-cols-2' : 'grid-cols-1'}`}>