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.

Sources/Shared/UI/Components/EmojiPickerView.swift

@@ -0,0 +1,92 @@
+import SwiftUI
+
+/// A reusable emoji picker: category tabs on the bottom and a grid of emojis
+/// for the selected category. Used both for reactions and for inserting an
+/// emoji into the composer.
+struct EmojiPickerView: View {
+    let onSelect: (String) -> Void
+
+    @Environment(\.dismiss) private var dismiss
+    @State private var selectedCategoryID = EmojiCatalog.categories.first?.id ?? ""
+
+    private let columns = [GridItem(.adaptive(minimum: 44), spacing: 4)]
+
+    private var selectedCategory: EmojiCategory {
+        EmojiCatalog.categories.first { $0.id == selectedCategoryID }
+            ?? EmojiCatalog.categories[0]
+    }
+
+    var body: some View {
+        VStack(spacing: 0) {
+            header
+
+            ScrollView {
+                LazyVGrid(columns: columns, spacing: 6) {
+                    ForEach(selectedCategory.emojis, id: \.self) { emoji in
+                        Button {
+                            onSelect(emoji)
+                            dismiss()
+                        } label: {
+                            Text(emoji)
+                                .font(.system(size: 28))
+                                .frame(width: 46, height: 46)
+                                .contentShape(Rectangle())
+                        }
+                        .buttonStyle(.plain)
+                        .accessibilityLabel(emoji)
+                    }
+                }
+                .padding(.horizontal, 12)
+                .padding(.top, 8)
+                .padding(.bottom, 12)
+            }
+
+            Divider()
+
+            categorySelector
+                .padding(.vertical, 8)
+        }
+        .frame(minHeight: 360)
+#if os(macOS)
+        .frame(minWidth: 380)
+#endif
+    }
+
+    private var header: some View {
+        HStack {
+            Text("Выберите эмодзи")
+                .font(.headline)
+            Spacer()
+            Button("Готово") { dismiss() }
+        }
+        .padding(.horizontal, 16)
+        .padding(.vertical, 12)
+    }
+
+    private var categorySelector: some View {
+        ScrollView(.horizontal, showsIndicators: false) {
+            HStack(spacing: 6) {
+                ForEach(EmojiCatalog.categories) { category in
+                    let isSelected = category.id == selectedCategoryID
+                    Button {
+                        selectedCategoryID = category.id
+                    } label: {
+                        Image(systemName: category.symbol)
+                            .font(.system(size: 18, weight: .medium))
+                            .foregroundStyle(isSelected ? Color.accentColor : Color.secondary)
+                            .frame(width: 44, height: 44)
+                            .background(
+                                isSelected
+                                    ? Color.accentColor.opacity(0.15)
+                                    : Color.clear,
+                                in: RoundedRectangle(cornerRadius: 10, style: .continuous)
+                            )
+                    }
+                    .buttonStyle(.plain)
+                    .accessibilityLabel(category.title)
+                }
+            }
+            .padding(.horizontal, 12)
+        }
+    }
+}

Sources/Shared/UI/Components/MessageBubble.swift

@@ -23,6 +23,7 @@ struct MessageBubble: View {
     let onDelete: () -> Void
     let onReplyTap: (String) -> Void
     let onReact: (String) -> Void
+    let onReactPicker: () -> Void
 
     @State private var replySwipeOffset: CGFloat = 0
     @State private var replySwipeArmed = false
@@ -56,11 +57,7 @@ struct MessageBubble: View {
         .contextMenu {
             if !isSelectionMode {
                 if message.canBeReactedTo {
-                    Menu {
-                        ForEach(MessageReactionPolicy.quickChoices, id: \.self) { emoji in
-                            Button(emoji) { onReact(emoji) }
-                        }
-                    } label: {
+                    Button(action: onReactPicker) {
                         Label("Реакция", systemImage: "face.smiling")
                     }
                 }