fix(account-settings): clear stale pw error on input + live header avatar update

- Password form errors (wrong pw, mismatch) now clear on first keystroke
  in any password field instead of persisting until next submit.
- Avatar upload now bumps avatarVersion in auth store and sets hasAvatar=true,
  so the header avatar switches to the uploaded image immediately without reload.
- Header img src uses ?v={avatarVersion} as cache-buster to force browser to
  fetch the new avatar when version increments.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/components/layout/header.tsx

@@ -13,7 +13,7 @@ export function Header() {
   const t = useTranslations();
   const tHeader = useTranslations('header');
   const setMobileOpen = useSidebarStore((s) => s.setMobileOpen);
-  const { user, setUser } = useAuthStore();
+  const { user, setUser, avatarVersion } = useAuthStore();
   const [dropdownOpen, setDropdownOpen] = useState(false);
   const dropdownRef = useRef<HTMLDivElement>(null);
   const pathname = usePathname();
@@ -112,7 +112,7 @@ export function Header() {
           >
             {user?.hasAvatar && !avatarError ? (
               <img
-                src="/api-proxy/users/me/avatar"
+                src={`/api-proxy/users/me/avatar?v=${avatarVersion}`}
                 alt=""
                 className="h-8 w-8 rounded-full object-cover"
                 onError={() => setAvatarError(true)}