Remove ToastProvider and related toast context functionality to streamline UI components and eliminate unused code. This change enhances overall code maintainability and reduces bundle size.

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

@@ -1,54 +0,0 @@
-import {
-  createContext,
-  useCallback,
-  useContext,
-  useMemo,
-  useState,
-  type ReactNode,
-} from 'react'
-
-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
-
-  // Литерал в value пересоздавался бы на каждый рендер провайдера и перерисовывал всех потребителей
-  // контекста, даже когда список тостов не менялся.
-  const value = useMemo(() => ({ toasts, dismiss }), [toasts, dismiss])
-
-  return <ToastContext value={value}>{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). */
-export const toast = {
-  success: (message: string) => pushImpl?.(message, 'success'),
-  error: (message: string) => pushImpl?.(message, 'error'),
-  message: (message: string) => pushImpl?.(message, 'default'),
-}