Notes tab: shared and private notes and checklists; icon-only menu rail on short windows

- notes.js and the Notes tab: private, family or chosen-people sharing; checklist items change one at a time (no overwrites), with who ticked them; open lists refresh live; stale text edits are refused
- Pin, colour, archive, search, filters, ready-made lists, Share to Chat, send open items to Tasks
- The narrow menu rail shows icons only (names on hover) when the window is too short for labels
- Roadmap and README updated

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

public/sw.js

@@ -1,5 +1,5 @@
 // App-shell cache only; Seafile/API traffic always goes to the network.
-const CACHE = 'hub-v62';
+const CACHE = 'hub-v64';
 const SHARE = 'hub-share'; // files shared into the app from other apps, held until the person picks a folder
 const SHELL = ['/icon.svg', '/manifest.webmanifest', '/icons/icon-192.png', '/icons/apple-touch-icon.png'];