Add "Download app" screen for too small screens, translate strings

# Please enter the commit message for your changes. Lines starting

frontend/src/ui/components/chat/MessageContextMenu.tsx

@@ -176,17 +176,17 @@ export function MessageContextMenu({
         >
             <div className="context-menu-item" onClick={() => handleAction("reply")}>
                 <span className="material-symbols">reply</span>
-                Reply
+                Ответить
             </div>
             {isAuthor && (
                 <>
                     <div className="context-menu-item" onClick={() => handleAction("edit")}>
                         <span className="material-symbols">edit</span>
-                        Edit
+                        Редактировать
                     </div>
                     <div className="context-menu-item" onClick={() => handleAction("delete")}>
                         <span className="material-symbols">delete</span>
-                        Delete
+                        Удалить
                     </div>
                 </>
             )}

frontend/src/ui/components/chat/MessagePanelRenderer.tsx

@@ -41,8 +41,8 @@ export function MessagePanelRenderer({ panel, isChatSwitching }: MessagePanelRen
         
         // Cleanup function
         return () => {
-            if (panel && (panel as any).onStateChange) {
-                (panel as any).onStateChange = null;
+            if (panel && panel.onStateChange) {
+                panel.onStateChange = null;
             }
         };
     }, [panel]);
@@ -72,10 +72,10 @@ export function MessagePanelRenderer({ panel, isChatSwitching }: MessagePanelRen
                         <img src={defaultAvatar} alt="Avatar" className="chat-header-avatar" />
                         <div className="chat-header-info">
                             <div className="info-chat">
-                                <h4 id="chat-name">Select a chat</h4>
+                                <h4 id="chat-name">Выбор чата</h4>
                                 <p>
                                     <span className="online-status"></span>
-                                    Choose a chat to start messaging
+                                    Выберите чат, чтобы начать переписку
                                 </p>
                             </div>
                         </div>
@@ -88,7 +88,7 @@ export function MessagePanelRenderer({ panel, isChatSwitching }: MessagePanelRen
                             height: "100%",
                             color: "var(--mdui-color-on-surface-variant)"
                         }}>
-                            Select a chat from the sidebar to start messaging
+                            Выберите чат на боковой панели, чтобы начать переписку
                         </div>
                     </div>
                 </div>
@@ -128,7 +128,7 @@ export function MessagePanelRenderer({ panel, isChatSwitching }: MessagePanelRen
                             height: "100%",
                             color: "var(--mdui-color-on-surface-variant)"
                         }}>
-                            Loading messages...
+                            Загрузка сообщений...
                         </div>
                     </div>
                 ): (

frontend/src/ui/components/chat/ReplyMessageDialog.tsx

@@ -36,7 +36,7 @@ export function ReplyMessageDialog({ isOpen, onOpenChange, replyToMessage, onSen
     return (
         <MaterialDialog open={isOpen} onOpenChange={onOpenChange} close-on-overlay-click close-on-esc className="reply-dialog">
             <div className="dialog-content">
-                <h3>Reply to Message</h3>
+                <h3>Ответить на сообщение</h3>
                 <div className="reply-preview-dialog">
                     <div className="reply-content">
                         <span className="reply-username">{replyToMessage.username}</span>

frontend/src/ui/components/chat/UserProfileDialog.tsx

@@ -28,24 +28,24 @@ export function UserProfileDialog({ isOpen, onOpenChange, userProfile }: UserPro
                     <div className={`online-status ${userProfile.online ? "online" : "offline"}`}>
                         {userProfile.online ? (
                             <>
-                                <span className="online-indicator"></span> Online
+                                <span className="online-indicator"></span> Онлайн
                             </>
                         ) : (
                             <>
-                                <span className="offline-indicator"></span> Last seen {formatTime(userProfile.last_seen)}
+                                <span className="offline-indicator"></span> Последний заход {formatTime(userProfile.last_seen)}
                             </>
                         )}
                     </div>
                 </div>
                 <div className="bio-section">
-                    <label>Bio:</label>
+                    <label>О себе:</label>
                     <div className="bio-display">
                         {userProfile.bio || "No bio available."}
                     </div>
                 </div>
                 <div className="profile-stats">
                     <div className="stat">
-                        <span className="stat-label">Member since:</span>
+                        <span className="stat-label">Зарегистрирован:</span>
                         <span className="stat-value member-since">{formatTime(userProfile.created_at)}</span>
                     </div>
                     <div className="stat">