style(layout): align mobile drawer spacing with Figma 4164-5336

Drawer top: drop nav pt-2 so the first menu item sits flush with the
drawer top edge per Figma frame 173 (first item y matches drawer y).

Drawer bottom: raise CTA bottom inset from 20px to 34px so the gap
between the 链接钱包 button and the drawer's bottom edge matches the
Figma measurement (Btn Primary bottom y=25041 vs drawer bottom y=25075).
The safe-area-inset env() still wins on devices with a larger inset.

src/layouts/PublicLayout.tsx

@@ -715,7 +715,7 @@ export function PublicLayout() {
           ref={menuRef}
           className={`${headerMenuAnimationClass} fixed inset-x-0 bottom-0 top-[64px] z-50 flex flex-col bg-ark-bg/90 backdrop-blur-xl md:top-[70px] min-[1000px]:hidden`}
         >
-          <nav className="flex-1 overflow-y-auto px-5 pt-2">
+          <nav className="flex-1 overflow-y-auto px-5">
             {(
               [
                 {
@@ -760,7 +760,7 @@ export function PublicLayout() {
               </Link>
             ))}
           </nav>
-          <div className="px-5 pb-[max(env(safe-area-inset-bottom),20px)] pt-4">
+          <div className="px-5 pb-[max(env(safe-area-inset-bottom),34px)] pt-4">
             <WalletButton compact onOpenLogin={() => setOpen(false)} />
           </div>
         </div>