🤖 Make window size responsive to screen dimensions (#339)

Calculates window size as 80% of primary display dimensions instead of
using fixed 1600×1000 size.

Uses Electron's `screen.getPrimaryDisplay().workArea` to detect
available screen space (excluding taskbars/menubars), then sizes the
window to 80% of that space with a minimum floor of 1200×800 for smaller
displays.

**Examples:**
- 1920×1080 display → 1536×864 window
- 2560×1440 display → 2048×1152 window
- 3840×2160 display (4K) → 3072×1728 window

_Generated with `cmux`_

Author: ammar-agent

src/main.ts

@@ -3,7 +3,15 @@ import "source-map-support/register";
 import "disposablestack/auto";
 
 import type { MenuItemConstructorOptions } from "electron";
-import { app, BrowserWindow, ipcMain as electronIpcMain, Menu, shell, dialog } from "electron";
+import {
+  app,
+  BrowserWindow,
+  ipcMain as electronIpcMain,
+  Menu,
+  shell,
+  dialog,
+  screen,
+} from "electron";
 import * as fs from "fs";
 import * as path from "path";
 import type { Config } from "./config";
@@ -314,9 +322,16 @@ function createWindow() {
     throw new Error("Services must be loaded before creating window");
   }
 
+  // Calculate window size based on screen dimensions (80% of available space)
+  const primaryDisplay = screen.getPrimaryDisplay();
+  const { width: screenWidth, height: screenHeight } = primaryDisplay.workArea;
+
+  const windowWidth = Math.max(1200, Math.floor(screenWidth * 0.8));
+  const windowHeight = Math.max(800, Math.floor(screenHeight * 0.8));
+
   mainWindow = new BrowserWindow({
-    width: 1200,
-    height: 800,
+    width: windowWidth,
+    height: windowHeight,
     webPreferences: {
       nodeIntegration: false,
       contextIsolation: true,