fix(auth): mount react-hot-toast Toaster so login/register feedback is visible

[AnushKamble]

Hi @rdodiya,
Login.jsx and Register.jsx use react-hot-toast (toast.success, toast.error), but the app never renders a component. Toasts are triggered but not shown, so users get no visible feedback on login failure, validation errors, or successful registration.

Expected behavior: Success and error toasts appear (e.g. top-right) when auth actions complete.

Actual behavior: No toast UI appears; only console/network feedback is available.

Expected outcome

• Failed login shows an error toast.
• Successful login shows a success toast (if applicable).
• Register flow shows toasts on success/failure.
• No duplicate instances.
• No new console errors.

Acceptance criteria

• from react-hot-toast is rendered in the React tree.
• Login error path displays a visible toast.
• Login success path displays a visible toast (when credentials are valid).
• Change is limited to minimal files (typically App.jsx or a single layout).

[AnushKamble]

I’d like to work on this issue as part of GSSoC 2026. Please assign this issue to me so I can open a focused PR.
Thanks!