feat: add toast notifications for successful and failed login attempts

distribution_fe/app/(auth)/login/page.tsx

@@ -7,6 +7,7 @@ import Image from 'next/image'
 import { Space_Grotesk } from 'next/font/google'
 import { useAuth } from '@/contexts/auth-context'
 import { getApiError } from '@/lib/api'
+import { toast } from '@/components/ui/toast'
 import { Input } from '@/components/ui/input'
 import { Label } from '@/components/ui/label'
 import { Button } from '@/components/ui/button'
@@ -32,8 +33,11 @@ export default function LoginPage() {
     setSubmitting(true)
     try {
       await login(identifier, password)
+      toast.add({ title: 'Signed in successfully', type: 'success' })
     } catch (err) {
-      setError(getApiError(err))
+      const message = getApiError(err)
+      setError(message)
+      toast.add({ title: 'Sign in failed', description: message, type: 'error' })
     } finally {
       setSubmitting(false)
     }