feat(web): complete groups/contacts/favorites/settings/calls/system domains + extensive review-round fixes

Rounds out the full rewrite with the remaining feature domains: group
management (admin panel, mute, files, announcements, QR-based invite/join),
contacts (friend profile, add-friend, blocklist, new-friends), favorites
(real media rendering across text/image/video/voice/file/link), settings
(profile/security/privacy/general/about), calls (Agora-backed audio/video
signaling + call history), and system messages/file assistant.

Also folds in a large batch of live-verified fixes surfaced by repeated
fresh code-review passes and hands-on E2E testing against the real
backend, including: WS reconnect not resubscribing any topic after a
disconnect, missing x-im-client-mid on every send path (protocol
compliance for retry dedup), group mute/member-settings/self-profile
endpoint corrections, relationship-state type fixes across search/QR/
friend-profile, tenant-switch logout gap, password-policy now read from
the real per-tenant config instead of guessed, NavRail highlight/
aria-current desync, several call-state-machine races, and responsive
layout fixes across all four breakpoints (mobile/tablet/laptop/desktop)
including a full mobile rebuild of favorites, call UI, and the settings
home/sub-list split.

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

web/src/app/Icon.tsx

@@ -1,7 +1,10 @@
-/** Thin wrapper around a Material Icons ligature glyph (font loaded in index.html). */
+/** Thin wrapper around a Material Icons ligature glyph (font loaded in index.html).
+ *  Always `aria-hidden` -- the glyph's DOM text is the icon's internal ligature name (e.g.
+ *  "arrow_back_ios_new"), never something a screen reader should announce. An icon-only
+ *  interactive element (button/link with no visible text) must set its own `aria-label`. */
 export function Icon({ name, className = '', style }: { name: string; className?: string; style?: React.CSSProperties }) {
   return (
-    <i className={`material-icons select-none ${className}`} style={style}>
+    <i aria-hidden="true" className={`material-icons select-none ${className}`} style={style}>
       {name}
     </i>
   );