feat(library): show playtime per platform on game detail

Hero and library card show the set total. Fall back to the
row's own minutes when the API sends no total.

src/pages/GameDetail.jsx

@@ -18,6 +18,7 @@ import EditionsCard from '../components/EditionsCard.jsx';
 import OwnersCard from '../components/people/OwnersCard.jsx';
 import GameMergeDialog from '../components/GameMergeDialog.jsx';
 import LinkGameDialog from '../components/LinkGameDialog.jsx';
+import PlatformsCard from '../components/PlatformsCard.jsx';
 import PlayingHint from '../components/PlayingHint.jsx';
 import useCurrentUser from '../hooks/useCurrentUser.js';
 import useGame from '../hooks/useGame.js';
@@ -110,6 +111,8 @@ export default function GameDetail() {
                                      if (data.editions?.length) reload();
                                  }}/>
 
+                    <PlatformsCard game={data}/>
+
                     <EditionsCard game={data} auditor={auditor} onRequest={() => setLinking(true)} onChanged={reload}/>
 
                     <OwnersCard key={`owners-${data.appid}`} appid={data.appid}/>

src/pages/GameLibrary.jsx

@@ -363,7 +363,7 @@ export default function GameLibrary() {
                                     )}
                                     <Badge variant="secondary" className="tabular-nums">
                                         <Clock className="size-3"/>
-                                        {formatPlaytime(g.playtimeMinutes)}
+                                        {formatPlaytime(g.totalPlaytimeMinutes ?? g.playtimeMinutes)}
                                     </Badge>
                                     <ChevronRight className="size-4 text-muted-foreground"/>
                                 </Link>

src/pages/GameLibrary.test.jsx

@@ -235,6 +235,16 @@ describe('GameLibrary short games', () => {
         expect(screen.queryByText('Steam')).toBeNull();
     });
 
+    it('showsTheSetTotalPlaytimeOnTheCard_AndTheOwnMinutesWithoutATotal', async () => {
+        answer([{appid: 220, name: 'Half-Life 2', playtimeMinutes: 600, totalPlaytimeMinutes: 3600, status: 'BACKLOG'},
+            {appid: 620, name: 'Portal 2', playtimeMinutes: 1200, status: 'BACKLOG'}]);
+        renderLibrary();
+
+        expect(await screen.findByText('60h')).toBeTruthy();
+        expect(screen.getByText('20h')).toBeTruthy();
+        expect(screen.queryByText('10h')).toBeNull();
+    });
+
     it('leaves the hidden games with a status click', async () => {
         const lib = renderLibrary('/library?hidden=true');
         await waitFor(() => expect(fetch).toHaveBeenCalled());