feat: Implement an Electron-based broadcasting client with screen/window and audio source selection, including Pipewire integration, and add auto-unmute to the viewer.

client/preload.js

@@ -0,0 +1,9 @@
+const { contextBridge, ipcRenderer } = require('electron');
+
+contextBridge.exposeInMainWorld('electronAPI', {
+    getSources: () => ipcRenderer.invoke('get-sources'),
+    getAudioApps: () => ipcRenderer.invoke('get-audio-apps'),
+    linkAppAudio: (appName) => ipcRenderer.invoke('link-app-audio', appName),
+    getConfig: () => ipcRenderer.invoke('get-config'),
+    saveConfig: (config) => ipcRenderer.invoke('save-config', config)
+});