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>

vite.config.ts

@@ -1,8 +1,10 @@
 import { defineConfig } from 'vite';
 import { svelte } from '@sveltejs/vite-plugin-svelte';
 
-export default defineConfig({
+export default defineConfig(({ mode }) => ({
   base: './',
   plugins: [svelte()],
-  build: { target: 'chrome120', outDir: 'dist', emptyOutDir: true }
-});
+  build: { target: 'chrome120', outDir: 'dist', emptyOutDir: true },
+  // npm run dev:web: the page comes from Vite, the API from the proxy that script starts next to it
+  server: mode === 'web' ? { proxy: { '/api': { target: 'http://127.0.0.1:8080', ws: true } } } : undefined
+}));