Add the browser version, a toolbar, description previews and hints

Browser version
- Self-hosted proxy (server/) that serves the web build and bridges WebSocket
  connections to Mumble servers over TLS, with a server allowlist or allow-any mode
- WebSocket transport and a browser platform layer; identities live in the browser
- npm run build:web, dev:web, proxy and test:e2e:web; proxy unit tests

Interface
- Toolbar next to mute and deafen: description editor, settings, expand or collapse all
- Channels with a description show a marker; resting on the row previews it
- Collapse all keeps channels with people open
- Hints (title tooltips) can be switched on in a new Accessibility settings tab
- New identities can set the username suggested when connecting
- Own user information tells the client address from the one the server sees

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/lib/tray.svelte.ts

@@ -1,4 +1,4 @@
-import { native } from './native.ts';
+import { desktop } from './native.ts';
 import { ICON_PATHS } from './icons.ts';
 import { session, sessions } from './session.svelte.ts';
 import { voice, type TransmitMode } from './audio/voice.svelte.ts';
@@ -40,8 +40,8 @@ function drawIcon(look: TrayLook): string {
 
 // Mirrors voice state into the system tray and handles its menu
 export function startTray(): void {
-  if (!native) return;
-  const api = native;
+  if (!desktop) return;
+  const api = desktop;
 
   $effect.root(() => {
     $effect(() => {