Have terminal chat align with xterm element

We didn't do this originally in order to hide the shell integration decoration,
but since that is not longer typical we can padd things out to align closer with
the editor

Author: Tyriar

src/vs/workbench/contrib/terminalContrib/chat/browser/terminalChatWidget.ts

@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import type { Terminal as RawXtermTerminal } from '@xterm/xterm';
-import { Dimension, IFocusTracker, trackFocus } from 'vs/base/browser/dom';
+import { Dimension, getActiveWindow, IFocusTracker, trackFocus } from 'vs/base/browser/dom';
 import { Event } from 'vs/base/common/event';
 import { Disposable, toDisposable } from 'vs/base/common/lifecycle';
 import { MicrotaskDelay } from 'vs/base/common/symbols';
@@ -100,11 +100,18 @@ export class TerminalChatWidget extends Disposable {
 	}
 
 	private _doLayout(heightInPixel: number) {
-		const width = Math.min(640, this._terminalElement.clientWidth - 12/* padding */ - 2/* border */ - Constants.HorizontalMargin);
+		const xtermElement = this._xterm.raw!.element;
+		if (!xtermElement) {
+			return;
+		}
+		const style = getActiveWindow().getComputedStyle(xtermElement);
+		const xtermPadding = parseInt(style.paddingLeft) + parseInt(style.paddingRight);
+		const width = Math.min(640, xtermElement.clientWidth - 12/* padding */ - 2/* border */ - Constants.HorizontalMargin - xtermPadding);
 		const height = Math.min(480, heightInPixel, this._getTerminalWrapperHeight() ?? Number.MAX_SAFE_INTEGER);
 		if (width === 0 || height === 0) {
 			return;
 		}
+		this._container.style.paddingLeft = style.paddingLeft;
 		this._dimension = new Dimension(width, height);
 		this._inlineChatWidget.layout(this._dimension);