Add disable timer setting and fix per-question time limits

Add a 'Question Timer' toggle to game settings that lets the host disable
the countdown timer. When disabled, questions show ∞ instead of a countdown,
the host gets an 'End Question' button to manually advance, and all correct
answers receive maximum points.

Also fix a bug where per-question time limits were ignored — the timer and
scoring always used the hardcoded 20-second default instead of each question's
individual timeLimit.

App.tsx

@@ -106,7 +106,8 @@ function App() {
     kickPlayer,
     leaveGame,
     connectedPlayerIds,
-    setHostName
+    setHostName,
+    endQuestion,
   } = useGame(defaultConfig);
 
   const handleSaveQuiz = async () => {
@@ -275,6 +276,8 @@ function App() {
               hasAnswered={hasAnswered}
               lastPointsEarned={lastPointsEarned}
               hostPlays={gameConfig.hostParticipates}
+              timerEnabled={gameConfig.timerEnabled}
+              onEndQuestion={role === 'HOST' ? endQuestion : undefined}
             />
           ) : role === 'CLIENT' && hasAnswered ? (
             <div className="flex flex-col items-center justify-center h-screen">