Remove TypeScript path mappings in favor of relative imports

Fixes https://github.com/xtermjs/xterm.js/issues/5896

TypeScript path mappings for common/*, browser/*, and headless/*
were not rewritten in emitted JavaScript, which forced webpack resolve
aliases and NODE_PATH workarounds so runtime could resolve modules.
That added build complexity and broke tooling such as ESLint import/no-cycle.

Changes:
- Convert ~750 imports across src/, addons/, and test/ to relative paths
- Remove common/browser/headless paths and src catch-all mappings from tsconfigs
  (keep @xterm/addon-* demo and addon typings paths)
- Remove webpack resolve.alias for common, browser, headless, and vs
- Drop NODE_PATH from unit tests, benchmarks, and VS Code launch config
- Fix addon-image IIPImageStorage to import ./Types after removing catch-all *

Verified: npm run build, esbuild, package, package-headless
Co-authored-by: Cursor <cursoragent@cursor.com>

src/browser/renderer/shared/RendererUtils.test.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { computeNextVariantOffset } from 'browser/renderer/shared/RendererUtils';
+import { computeNextVariantOffset } from './RendererUtils';
 import { assert } from 'chai';
 
 describe('RendererUtils', () => {

src/browser/renderer/shared/RendererUtils.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { IDimensions, IRenderDimensions } from 'browser/renderer/shared/Types';
+import { IDimensions, IRenderDimensions } from './Types';
 
 export function throwIfFalsy<T>(value: T | undefined | null): T {
   if (!value) {

src/browser/renderer/shared/SelectionRenderModel.ts

@@ -3,8 +3,8 @@
  * @license MIT
  */
 
-import { ITerminal } from 'browser/Types';
-import { ISelectionRenderModel } from 'browser/renderer/shared/Types';
+import { ITerminal } from '../../Types';
+import { ISelectionRenderModel } from './Types';
 import { Terminal } from '@xterm/xterm';
 
 class SelectionRenderModel implements ISelectionRenderModel {

src/browser/renderer/shared/TextBlinkStateManager.test.ts

@@ -4,10 +4,10 @@
  */
 
 import { assert } from 'chai';
-import { TextBlinkStateManager } from 'browser/renderer/shared/TextBlinkStateManager';
-import { MockOptionsService } from 'common/TestUtils.test';
-import type { ICoreBrowserService } from 'browser/services/Services';
-import { Emitter } from 'common/Event';
+import { TextBlinkStateManager } from './TextBlinkStateManager';
+import { MockOptionsService } from '../../../common/TestUtils.test';
+import type { ICoreBrowserService } from '../../services/Services';
+import { Emitter } from '../../../common/Event';
 
 class FakeWindow {
   public nextId = 1;

src/browser/renderer/shared/TextBlinkStateManager.ts

@@ -3,9 +3,9 @@
  * @license MIT
  */
 
-import { ICoreBrowserService } from 'browser/services/Services';
-import { Disposable, toDisposable } from 'common/Lifecycle';
-import { IOptionsService } from 'common/services/Services';
+import { ICoreBrowserService } from '../../services/Services';
+import { Disposable, toDisposable } from '../../../common/Lifecycle';
+import { IOptionsService } from '../../../common/services/Services';
 
 export class TextBlinkStateManager extends Disposable {
   private _intervalDuration: number = 0;

src/browser/renderer/shared/Types.ts

@@ -4,9 +4,9 @@
  */
 
 import { Terminal } from '@xterm/xterm';
-import { ITerminal } from 'browser/Types';
-import { IDisposable } from 'common/Types';
-import type { IEvent } from 'common/Event';
+import { ITerminal } from '../../Types';
+import { IDisposable } from '../../../common/Types';
+import type { IEvent } from '../../../common/Event';
 
 export interface IDimensions {
   width: number;