feat: Aether Drift UI polish — popout redesign, sidebar cleanup, status dot fix

- Redesign UserProfilePopout with glass material, viewport clamping, flow-based
  avatar layout, and subtle send-message button
- Server sidebar: downsize icons to 40px (matching prototype), remove nonfunctional
  Explore button, add separator before action buttons, replace Tooltip with native
  title, remove hover boxShadow artifacts
- Avatar status dot: fixed 12px size with semi-transparent border for universal
  cutout effect matching the design prototype
- MemberListToggleButton: distinct three-person icon (was duplicate of Add Friends)
- FriendsPage: fix Add Friend button contrast (dark text on mint background)
- ChannelSidebar: rename Nitro/Shop to Coming Soon placeholders

packages/web/src/components/layout/MemberListToggleButton.tsx

@@ -14,7 +14,7 @@ export function MemberListToggleButton() {
       title="Toggle Member List"
     >
       <svg width="24" height="24" viewBox="0 0 24 24" fill="currentColor">
-        <path d="M14 8.00598C14 10.211 12.206 12.006 10 12.006C7.795 12.006 6 10.211 6 8.00598C6 5.80098 7.794 4.00598 10 4.00598C12.206 4.00598 14 5.80098 14 8.00598ZM2 19.006C2 15.473 5.29 13.006 10 13.006C14.711 13.006 18 15.473 18 19.006V20.006H2V19.006ZM20 20.006H22V19.006C22 16.451 20.178 14.471 17.532 13.471C19.461 14.601 20 16.561 20 19.006V20.006Z" />
+        <path d="M12 12.75c1.63 0 3.07.39 4.24.9 1.08.48 1.76 1.56 1.76 2.73V18H6v-1.61c0-1.18.68-2.26 1.76-2.73 1.17-.52 2.61-.91 4.24-.91zM4 13c1.1 0 2-.9 2-2s-.9-2-2-2-2 .9-2 2 .9 2 2 2zm1.13 1.1c-.37-.06-.74-.1-1.13-.1-.99 0-1.93.21-2.78.58A2.01 2.01 0 0 0 0 16.43V18h4.5v-1.61c0-.83.23-1.61.63-2.29zM20 13c1.1 0 2-.9 2-2s-.9-2-2-2-2 .9-2 2 .9 2 2 2zm4 3.43c0-.81-.48-1.53-1.22-1.85A6.95 6.95 0 0 0 20 14c-.39 0-.76.04-1.13.1.4.68.63 1.46.63 2.29V18H24v-1.57zM12 6c1.66 0 3 1.34 3 3s-1.34 3-3 3-3-1.34-3-3 1.34-3 3-3z" />
       </svg>
     </button>
   );