Hide game sheet sections and winner selection until game has started

Wrapped WinnerBadge, SheetSection grid, and WinnerCard components in conditional rendering based on `gameStarted` flag derived from game metadata's `started` property. Prevents display of game content in lobby state before host initiates gameplay.

frontend/src/App.jsx

@@ -622,6 +622,7 @@ export default function App() {
     : [];
 
   const isHost = !!(me?.id && gameMeta?.host_user_id && me.id === gameMeta.host_user_id);
+  const gameStarted = !!gameMeta?.started;
 
   return (
     <div style={styles.page}>
@@ -666,38 +667,43 @@ export default function App() {
           onStartGame={startGame}
         />
 
-        {/* Sieger Badge: zwischen Spiel und Verdächtigte Person */}
+        {gameStarted && (
-        <WinnerBadge
+          <WinnerBadge
-          winner={{
+            winner={{
-            display_name: gameMeta?.winner_display_name || "",
+              display_name: gameMeta?.winner_display_name || "",
-            email: gameMeta?.winner_email || "",
+              email: gameMeta?.winner_email || "",
-          }}
+            }}
-        />
+          />
+        )}
 
         <HelpModal open={helpOpen} onClose={() => setHelpOpen(false)} />
 
-        <div style={{ marginTop: 14, display: "grid", gap: 14 }}>
+        {gameStarted && (
-          {sections.map((sec) => (
+          <div style={{ marginTop: 14, display: "grid", gap: 14 }}>
-            <SheetSection
+            {sections.map((sec) => (
-              key={sec.key}
+              <SheetSection
-              title={sec.title}
+                key={sec.key}
-              entries={sec.entries}
+                title={sec.title}
-              pulseId={pulseId}
+                entries={sec.entries}
-              onCycleStatus={cycleStatus}
+                pulseId={pulseId}
-              onToggleTag={toggleTag}
+                onCycleStatus={cycleStatus}
-              displayTag={displayTag}
+                onToggleTag={toggleTag}
-            />
+                displayTag={displayTag}
-          ))}
+              />
-        </div>
+            ))}
+          </div>
+        )}
 
         {/* Host-only Winner Auswahl */}
-        <WinnerCard
+        {gameStarted && (
-          isHost={isHost}
+          <WinnerCard
-          members={members}
+            isHost={isHost}
-          winnerUserId={winnerUserId}
+            members={members}
-          setWinnerUserId={setWinnerUserId}
+            winnerUserId={winnerUserId}
-          onSave={saveWinner}
+            setWinnerUserId={setWinnerUserId}
-        />
+            onSave={saveWinner}
+          />
+        )}
 
         <div style={{ height: 24 }} />
       </div>