add server info screen, connection stats, and emoji picker

Server information (Monal-style):
- Add ServerInformation model and ServerInfoView reachable from
  Settings,
  showing server software (XEP-0092), disco#info identities and
  features,
  conference (MUC) services via disco#items, and STUN/TURN via XEP-0215.
- Add a curated XEP capability list with per-XEP success/error status
  derived
  from server/account disco features and connection flags.
- Detect PEP (0163) from account disco pubsub#* features, HTTP Upload
  (0363)
  from the main domain plus its components, and add Roster Versioning
  (0237),
  Pre-Authenticated Roster Subscription (0379), and SASL SCRAM Downgrade
  Protection (0474, neutral because Martin does not expose SSDP).

Connection statistics:
- Add LumaConnectionStatsModule, an XmppStanzaFilter registered before
  stream
  management, to count sent / acknowledged / received stanzas.
- Track last login and SMACKS session timestamps, and read SASL
  mechanisms
  and Client State Indication from the raw stream features.

MAM / OMEMO handling:
- Prefer a plaintext <body> fallback when OMEMO decryption fails instead
  of
  showing "failed to decrypt".
- Keep the optimistic text of our own outgoing message when its echo
  cannot
  be decrypted back, instead of replacing it with a placeholder.

Emoji picker:
- Add EmojiCatalog and a cross-platform EmojiPickerView.
- Open the picker for reactions (replacing the static quick list) and
  from
  the composer's smiley button, inserting the chosen emoji into the
  draft.

Scripts/verify.sh

@@ -537,8 +537,12 @@ grep -q 'urn:xmpp:reactions:0' Sources/Shared/XMPP/XMPPService.swift || {
   echo "XEP-0444 capability advertisement is missing"
   exit 1
 }
-grep -q 'MessageReactionPolicy.quickChoices' Sources/Shared/UI/Components/MessageBubble.swift || {
-  echo "Message reaction UI is missing"
+grep -q 'onReactPicker' Sources/Shared/UI/Components/MessageBubble.swift || {
+  echo "Message reaction picker is missing"
+  exit 1
+}
+grep -q 'EmojiPickerView' Sources/Shared/UI/ChatView.swift || {
+  echo "The emoji picker is not wired into the chat"
   exit 1
 }
 grep -q 'ChatStateNotificationsModule' Sources/Shared/XMPP/XMPPService.swift || {