Add pixel size support to resize()

[anthonykim1]

From: xtermjs/xterm.js#5619 (comment)

[anthonykim1]

I thought about renaming this to width, height but might be confusing since we dont have the pixelSize like in interfaces.ts

Maybe widthPixel, heightPixel would be the better

[anthonykim1]

Should I just create another interface PixelSize which would have field width, height?
That way we can just say simply say pixelSize here.

[anthonykim1]

xpixel, ypixel vs. width, height vs widthPixel, heightPixel 🥸

[anthonykim1]

Testing the pass through with js script with:

1. npm run build
2. node examples/test-pixel-resize.js

where test-pixe-resize.js

/**

• Test script to verify pixel size is passed to the pty.
• Run with: node examples/test-pixel-resize.js
  */
  import * as os from 'node:os';
  import * as pty from '../lib/index.js';

const isWindows = os.platform() === 'win32';
const shell = isWindows ? 'powershell.exe' : 'bash';

const ptyProcess = pty.spawn(shell, [], {
name: 'xterm-256color',
cols: 80,
rows: 24,
cwd: isWindows ? process.env.USERPROFILE : process.env.HOME,
env: process.env
});

ptyProcess.onData(data => process.stdout.write(data));

// On Unix, we can query the terminal size including pixel dimensions
// using the escape sequence: ESC [ 1 4 t (report window size in pixels)
// or use stty/resize commands, or write a small C program

if (!isWindows) {
// Method 1: Use stty size to get rows/cols (doesn't show pixels though)
console.log('\n--- Testing resize with pixel dimensions ---\n');

// Resize with pixel dimensions: 800x600 pixels
ptyProcess.resize(100, 30, { width: 800, height: 600 });
console.log('Resized to 100x30 chars, 800x600 pixels');

// Query window size - this C one-liner reads TIOCGWINSZ and prints all 4 values
ptyProcess.write(python3 -c " import fcntl, termios, struct buf = fcntl.ioctl(0, termios.TIOCGWINSZ, b'\\x00' * 8) rows, cols, xpixel, ypixel = struct.unpack('HHHH', buf) print(f'rows={rows}, cols={cols}, xpixel={xpixel}, ypixel={ypixel}') "\r);
}

setTimeout(() => {
ptyProcess.kill();
process.exit(0);
}, 3000);

TODO before merging:
Now I should test if this works when I symlink node-pty on xterm