Bump to v1.1.0 and bring all documentation current

Version bump in both pyproject.toml and package.json. Documentation
update covers everything shipped since v1.0.0 (direct messages,
message deletion, custom emoji, video attachments, DM/room email
notifications, active sessions, and more), and corrects claims that
had gone stale -- backend/README.md and DEPLOYMENT.md both still said
"no server-side session revocation" and backend/README.md said "no
custom/uploaded emoji," both now false.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -18,21 +18,26 @@ build plan.
 
 ## Features
 
-- **Auth & accounts** — session-based auth, invite-only signup (admin-issued
-  site invites or room invites, both delivered by email), password reset,
-  per-user light/dark/midnight/sunset presets plus a live theme builder for
-  fully custom, named, savable color themes.
-- **Rooms** — open and private rooms, owner/admin/member roles, invites,
-  room browsing/search, file/image galleries per room.
+- **Auth & accounts** — server-side, revocable sessions (see every device
+  you're logged in from and sign one out remotely), invite-only signup
+  (admin-issued site invites or room invites, both delivered by email),
+  password reset, per-user light/dark/midnight/sunset presets plus a live
+  theme builder for fully custom, named, savable color themes.
+- **Rooms & direct messages** — open and private rooms, owner/admin/member
+  roles, invites (with resend), room browsing/search, file/image galleries
+  per room, plus 1:1 direct messages with a collapsible sidebar section.
 - **Real-time chat** — WebSocket-based messaging with automatic reconnect
-  and backoff, Markdown rendering, @mentions with autocomplete and inline
-  highlighting, emoji reactions, message editing, image and file
-  attachments (drag-and-drop, paste, or picker) with inline previews for
-  images/PDFs/text/Markdown, unread indicators, and presence (online/away/
+  and backoff, Markdown rendering (headings with custom anchors, sub/
+  superscript, tables, and more), @mentions and #room-reference links with
+  autocomplete and inline highlighting, emoji reactions and shortcodes plus
+  site-wide custom/uploaded emoji, message editing and deletion, image/
+  video/file attachments (drag-and-drop, paste, or picker) with inline
+  previews and playback, unread indicators, and presence (online/away/
   offline, with a manual "appear offline" override).
-- **Notifications** — Web Push for offline/backgrounded members, with
-  per-type opt-in/out (mentions vs. all messages), plus in-app unread
-  badges.
+- **Notifications** — Web Push and native desktop notifications for
+  offline/backgrounded members, plus email: always-on for direct messages,
+  opt-in per room (first unread message and every mention), all alongside
+  in-app unread badges.
 - **PWA** — installable, offline-capable (cached room/message data, a
   dedicated offline banner), with automatic update detection that prompts
   a reload as soon as a new deploy goes live.