Implement rate limiting and enhance authentication flow

- Added rate limiting configuration for authentication endpoints, allowing customizable request limits via environment variables.
- Updated authentication flow to utilize HttpRequest for cookie management, ensuring secure handling of refresh tokens.
- Introduced a new endpoint to retrieve user subscription details.
- Enhanced the handling of Telegram bot token validation to prevent errors with empty tokens.
- Updated the application to serialize enums as strings for better documentation and compatibility with TypeScript.
- Improved test coverage for new features and adjustments in command handlers.

frontend/src/shared/ui/toast-store.tsx

@@ -0,0 +1,43 @@
+import { createContext, useCallback, useContext, useState, type ReactNode } from 'react'
+
+export type ToastVariant = 'default' | 'success' | 'error'
+export type ToastItem = { id: number; message: string; variant: ToastVariant }
+
+let nextId = 1
+let pushImpl: ((message: string, variant: ToastVariant) => void) | null = null
+
+type ToastContextValue = {
+  toasts: ToastItem[]
+  dismiss: (id: number) => void
+}
+
+const ToastContext = createContext<ToastContextValue | null>(null)
+
+export function ToastProvider({ children }: { children: ReactNode }) {
+  const [toasts, setToasts] = useState<ToastItem[]>([])
+
+  const push = useCallback((message: string, variant: ToastVariant) => {
+    setToasts((prev) => [...prev, { id: nextId++, message, variant }])
+  }, [])
+
+  const dismiss = useCallback((id: number) => {
+    setToasts((prev) => prev.filter((t) => t.id !== id))
+  }, [])
+
+  pushImpl = push
+
+  return <ToastContext value={{ toasts, dismiss }}>{children}</ToastContext>
+}
+
+export function useToastContext() {
+  const ctx = useContext(ToastContext)
+  if (!ctx) throw new Error('useToastContext must be used within ToastProvider')
+  return ctx
+}
+
+/** Императивный вызов из любого места (не только компонентов) — как sonner/react-hot-toast. */
+export const toast = {
+  success: (message: string) => pushImpl?.(message, 'success'),
+  error: (message: string) => pushImpl?.(message, 'error'),
+  message: (message: string) => pushImpl?.(message, 'default'),
+}