fix: NP overlay — more top padding, centered content, roomier topbar

- np-inner padding-top increased to max(safe-area, 36px)
- np-topbar margin-bottom 28→32px + gap:12px between buttons and tabs
- np-tabs flex:1 + flex:1 on each tab so they share space evenly, no overflow
- np-tab font-size 11→10px, padding tighter to fit small screens
- #np-player-view gains justify-content:center so art/controls float mid-screen

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

sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'ns-v28';
+const CACHE = 'ns-v29';
 const PRECACHE = ['/', 'index.html', 'styles.css', 'app.js', 'manifest.json', 'icon.svg'];
 const SKIP_PATHS = ['/rest/stream', '/rest/download', '/config.js'];