refactor(toast): ♻️ Enhance Toast component with new variants, improved styling, and accessibility features

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

codebase/@features/provider-website/frontend-public/src/components/Toast/Toast.tsx

@@ -0,0 +1,62 @@
+/**
+ * Toast — Global ephemeral notification system.
+ * Provides ToastProvider (wrap at root), useToast (trigger), and the rendered overlay.
+ */
+
+import { createContext, useContext, useState, useCallback, type ReactNode } from 'react';
+import styled, { keyframes } from '@lilith/ui-styled-components';
+
+interface ToastContextValue {
+  showToast: (message: string) => void;
+}
+
+const ToastContext = createContext<ToastContextValue>({ showToast: () => {} });
+
+export function useToast(): ToastContextValue {
+  return useContext(ToastContext);
+}
+
+const slideUp = keyframes`
+  from { opacity: 0; transform: translateY(8px); }
+  to   { opacity: 1; transform: translateY(0); }
+`;
+
+const ToastBanner = styled.div`
+  position: fixed;
+  bottom: 5.5rem;
+  left: 50%;
+  transform: translateX(-50%);
+  z-index: 300;
+  background: rgba(20, 20, 32, 0.95);
+  border: 1px solid rgba(212, 175, 55, 0.4);
+  color: #D4AF37;
+  font-size: 0.8rem;
+  font-weight: 500;
+  letter-spacing: 0.04em;
+  padding: 0.5rem 1rem;
+  border-radius: 9999px;
+  backdrop-filter: blur(8px);
+  -webkit-backdrop-filter: blur(8px);
+  box-shadow:
+    0 4px 16px rgba(0, 0, 0, 0.5),
+    0 0 20px rgba(212, 175, 55, 0.1);
+  white-space: nowrap;
+  pointer-events: none;
+  animation: ${slideUp} 180ms ease both;
+`;
+
+export function ToastProvider({ children }: { children: ReactNode }): ReactNode {
+  const [message, setMessage] = useState<string | null>(null);
+
+  const showToast = useCallback((msg: string): void => {
+    setMessage(msg);
+    setTimeout(() => setMessage(null), 2000);
+  }, []);
+
+  return (
+    <ToastContext.Provider value={{ showToast }}>
+      {children}
+      {message && <ToastBanner role="status" aria-live="polite">{message}</ToastBanner>}
+    </ToastContext.Provider>
+  );
+}