feat: artist-page scroll/search memory (android) + move APK button to bottom (web)

- Android: the artist page's main list and the "Alle anzeigen" album overlay
  (grid scroll + search query) are hoisted into the Artist/Explore ViewModels,
  so drilling into an album/artist and back keeps position + query. Covers the
  library artist and Deezer (Explore) artist screens.
- Web: the "Android App" download section now sits at the very bottom of
  Settings, below the Navidrome-Server (account) section.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

index.html

@@ -605,18 +605,6 @@
           <div id="s-cover-color-bg" class="toggle" onclick="this.classList.toggle('on')"></div>
         </div>
       </div>
-      <div class="settings-section" id="s-apk-section" style="display:none">
-        <h3 style="display:flex;align-items:center;gap:8px;margin-bottom:12px">
-          <span style="width:24px;height:24px;border-radius:6px;background:var(--surface2);display:inline-flex;align-items:center;justify-content:center;font-size:12px">🤖</span>
-          Android App
-        </h3>
-        <div style="font-size:12px;color:var(--text2);margin-bottom:10px;line-height:1.6">Installiere die NovaSonic Android-App direkt aufs Handy. <span id="s-apk-meta" style="color:var(--text3)"></span></div>
-        <a id="s-apk-btn" href="#" download style="display:inline-flex;align-items:center;gap:8px;padding:10px 16px;border-radius:10px;background:linear-gradient(135deg,var(--accent),var(--accent-dark));color:#fff;font-weight:700;font-size:13px;text-decoration:none;box-shadow:0 4px 12px var(--accent-glow)">
-          <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="7 10 12 15 17 10"/><line x1="12" y1="15" x2="12" y2="3"/></svg>
-          APK herunterladen
-        </a>
-        <div style="font-size:11px;color:var(--text3);margin-top:8px">Danach im Handy „Installation aus unbekannten Quellen" für den Browser erlauben.</div>
-      </div>
       <div class="settings-section">
         <h3 style="display:flex;align-items:center;gap:8px;margin-bottom:12px">
           <span style="width:24px;height:24px;border-radius:6px;background:var(--surface2);display:inline-flex;align-items:center;justify-content:center;font-size:12px">📊</span>
@@ -709,6 +697,18 @@
         <div class="field"><label>Benutzername</label><input id="s-user" type="text" placeholder="admin"></div>
         <div class="field"><label>Passwort</label><input id="s-pass" type="password" placeholder="(unverändert lassen)"></div>
       </div>
+      <div class="settings-section" id="s-apk-section" style="display:none">
+        <h3 style="display:flex;align-items:center;gap:8px;margin-bottom:12px">
+          <span style="width:24px;height:24px;border-radius:6px;background:var(--surface2);display:inline-flex;align-items:center;justify-content:center;font-size:12px">🤖</span>
+          Android App
+        </h3>
+        <div style="font-size:12px;color:var(--text2);margin-bottom:10px;line-height:1.6">Installiere die NovaSonic Android-App direkt aufs Handy. <span id="s-apk-meta" style="color:var(--text3)"></span></div>
+        <a id="s-apk-btn" href="#" download style="display:inline-flex;align-items:center;gap:8px;padding:10px 16px;border-radius:10px;background:linear-gradient(135deg,var(--accent),var(--accent-dark));color:#fff;font-weight:700;font-size:13px;text-decoration:none;box-shadow:0 4px 12px var(--accent-glow)">
+          <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="7 10 12 15 17 10"/><line x1="12" y1="15" x2="12" y2="3"/></svg>
+          APK herunterladen
+        </a>
+        <div style="font-size:11px;color:var(--text3);margin-top:8px">Danach im Handy „Installation aus unbekannten Quellen" für den Browser erlauben.</div>
+      </div>
     </div>
     <!-- Sticky footer -->
     <div style="display:flex;flex-direction:column;gap:8px;padding:12px 24px 16px;border-top:1px solid var(--border);flex-shrink:0;background:var(--surface);border-radius:0 0 18px 18px">