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/features/contacts/EmptyContactsMain.tsx

@@ -0,0 +1,10 @@
+import { Icon } from '@/app/Icon';
+
+export function EmptyContactsMain() {
+  return (
+    <div className="flex h-full w-full flex-col items-center justify-center gap-2 bg-surface-content text-text-tertiary-4">
+      <Icon name="person_search" className="!text-5xl" />
+      <span className="text-sm">选择一位联系人查看资料</span>
+    </div>
+  );
+}