feat(login): method-state login panel with quiet inline errors (#1469)

* feat(login): method-state login panel with quiet inline errors

The login panel now shows one method at a time (the pattern Swedish
users know from banks, Kivra and Fortnox): BankID as the hero state,
the email form as a peer state, and the remaining methods as two quiet
half-width chips under a single divider. The last successful method is
remembered in an accounted-login-method cookie, read server-side so a
returning password user gets the form on the first paint with no flash.

Error display drops the boxed banner everywhere: credential failures
render as one destructive sentence directly under the password field
(fields keep aria-invalid), and the reset-password action surfaces from
the second consecutive failure. BankID/Google failures, callback errors
and the session-timeout notice are single quiet lines at the top of the
panel (AttnLine for the informational one).

Also: password visibility toggle, webkit autofill repaint to the theme
surface, auth pages move from the gradient background to the app frame
tone, register/MFA/reset get the same backdrop for cross-page
coherence, and Skapa konto moves out of the panel into a footer line.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* feat(register): mirror the method-state panel on signup

Same treatment as the login page: BankID signup as the hero state, the
email form as a peer state (live password checklist kept), alternatives
as half-width chips under one divider, quiet-line notices instead of
the blue box, subtitle dropped, footer harmonized. Successful signup
persists the method hint so the user's first login opens correctly.
The BankID-verified email-collection step keeps its panel takeover.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

components/auth/GoogleAuthButton.tsx

@@ -40,7 +40,18 @@ function GoogleMark() {
  * The flow=oauth marker lets the callback tag failures so the login page
  * shows Google-specific copy instead of the email-confirmation framing.
  */
-export function GoogleAuthButton({ onError }: { onError: (message: string) => void }) {
+export function GoogleAuthButton({
+  onError,
+  compact = false,
+}: {
+  onError: (message: string) => void
+  /**
+   * Half-width alternative-method chip on the login panel: shows just the
+   * mark and "Google" (a brand name, never translated), with the full label
+   * kept as the accessible name.
+   */
+  compact?: boolean
+}) {
   const [isRedirecting, setIsRedirecting] = useState(false)
   const supabase = createClient()
   const tAuth = useTranslations('auth')
@@ -70,16 +81,19 @@ export function GoogleAuthButton({ onError }: { onError: (message: string) => vo
     <Button
       type="button"
       variant="outline"
-      className="w-full h-11"
+      className={compact ? 'h-10 w-full gap-2' : 'w-full h-11'}
       onClick={handleClick}
       disabled={isRedirecting}
+      aria-label={tAuth('continue_with_google')}
     >
       {isRedirecting ? (
-        <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+        <Loader2 className={compact ? 'h-4 w-4 animate-spin' : 'mr-2 h-4 w-4 animate-spin'} />
       ) : (
-        <span className="mr-2 flex items-center"><GoogleMark /></span>
+        <span className={compact ? 'flex items-center' : 'mr-2 flex items-center'}>
+          <GoogleMark />
+        </span>
       )}
-      {tAuth('continue_with_google')}
+      {compact ? 'Google' : tAuth('continue_with_google')}
     </Button>
   )
 }