Split app.js into one script per feature; versioning covers every public file; README for the new features

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

public/index.html

@@ -60,6 +60,19 @@
 <script src="/music-extras.js"></script>
 <script src="/calendar-views.js"></script>
 <script src="/app.js"></script>
+<script src="/search-view.js"></script>
+<script src="/calendar.js"></script>
+<script src="/tasks.js"></script>
+<script src="/audiobooks.js"></script>
+<script src="/music.js"></script>
+<script src="/player.js"></script>
+<script src="/lyrics-view.js"></script>
+<script src="/settings.js"></script>
+<script src="/files.js"></script>
+<script src="/sheets.js"></script>
+<script src="/file-actions.js"></script>
+<script src="/signal-view.js"></script>
+<script src="/boot.js"></script>
 <script src="/shell.js"></script>
 </body>
 </html>