fix(login): center text for generic IDP buttons without icons (#12211)

Closes #12182

# Which Problems Are Solved

Generic IDP buttons (OIDC, SAML, LDAP, JWT) used pl-20 to approximate
icon offset alignment, but since they have no icon, the text appeared
misaligned compared to branded IDPs (Google, Microsoft, Apple).

# How the Problems Are Solved

Replaced the left-padding hack with centered text so generic IDP names
display cleanly within the button.

before:

<img width="392" height="290" alt="Screenshot 2026-05-28 at 12 03 21"
src="https://github.com/user-attachments/assets/64c4e8eb-caec-4742-b61c-e3b0c5093dd7"
/>

after:

<img width="392" height="289" alt="Screenshot 2026-05-28 at 12 07 27"
src="https://github.com/user-attachments/assets/d1faf1f4-0aab-475f-8801-15b461e15da4"
/>

apps/login/src/components/idps/sign-in-with-generic.tsx

@@ -5,10 +5,10 @@ import { BaseButton, SignInWithIdentityProviderProps } from "./base-button";
 
 export const SignInWithGeneric = forwardRef<HTMLButtonElement, SignInWithIdentityProviderProps>(
   function SignInWithGeneric(props, ref) {
-    const { children, name = "", className = "h-[50px] pl-20", ...restProps } = props;
+    const { children, name = "", className = "h-[50px]", ...restProps } = props;
     return (
       <BaseButton {...restProps} ref={ref} className={className}>
-        {children ? children : <span>{name}</span>}
+        {children ? children : <span className="w-full text-center">{name}</span>}
       </BaseButton>
     );
   },