fix: clear auth form errors

- Clear error state before submitting credentials in login page
- Clear error state before submitting registration in register page
- Add optional onFieldChange callback to AuthForm to clear parent errors when fields change
- Add role="alert" to error paragraph for accessibility

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/web/src/pages/login-page.tsx

@@ -30,7 +30,11 @@ export function LoginPage() {
           isSubmitting={mutation.isPending}
           error={error}
           googleOAuthEnabled={Boolean(meQuery.data?.features.googleOAuthEnabled)}
-          onSubmit={async ({ email, password }) => mutation.mutateAsync({ email, password })}
+          onSubmit={async ({ email, password }) => {
+            setError(null);
+            return mutation.mutateAsync({ email, password });
+          }}
+          onFieldChange={() => setError(null)}
         />
         <p className="text-center text-sm text-muted-foreground">
           Belum punya akun? <Link className="text-primary" to="/register">Daftar</Link>

apps/web/src/pages/register-page.tsx

@@ -30,7 +30,11 @@ export function RegisterPage() {
           isSubmitting={mutation.isPending}
           error={error}
           googleOAuthEnabled={Boolean(meQuery.data?.features.googleOAuthEnabled)}
-          onSubmit={async ({ name, email, password }) => mutation.mutateAsync({ name: name ?? '', email, password })}
+          onSubmit={async ({ name, email, password }) => {
+            setError(null);
+            return mutation.mutateAsync({ name: name ?? '', email, password });
+          }}
+          onFieldChange={() => setError(null)}
         />
         <p className="text-center text-sm text-muted-foreground">
           Sudah punya akun? <Link className="text-primary" to="/login">Masuk</Link>