Keep path mappings for addons after core migration

Follow-up to https://github.com/xtermjs/xterm.js/issues/5896 / PR #5966.

Converting addons to ../../../src/common relative imports broke unit tests:
esbuild emits addon code under addons/*/out-esbuild/ without mirroring the
shared tree, so Node could not load TypeScript sources at runtime
(Cannot find module '../../../src/common/Lifecycle').

Core src/, test/, and headless continue to use relative imports with no
common/* path mappings. Addons keep the prior model until build layout
can share out-esbuild the same way as the main package.

Changes:
- Restore common/* and browser/* paths in addon src/test/benchmark tsconfigs
- Revert addon imports to common/ and browser/ path-mapped specifiers
- Restore NODE_PATH=out-esbuild in bin/test_unit.js for Mocha resolution
- Restore webpack resolve.alias on addons that bundle against out/

Fixes CI test-unit failures on remove-path-mappings-5896.

Co-authored-by: Cursor <cursoragent@cursor.com>

addons/addon-progress/src/ProgressAddon.ts

@@ -5,7 +5,7 @@
 
 import type { Terminal, ITerminalAddon, IDisposable } from '@xterm/xterm';
 import type { ProgressAddon as IProgressApi, IProgressState } from '@xterm/addon-progress';
-import type { Emitter, IEvent } from '../../../src/common/Event';
+import type { Emitter, IEvent } from 'common/Event';
 
 
 const enum ProgressType {

addons/addon-progress/src/tsconfig.json

@@ -15,6 +15,12 @@
       "../../../node_modules/@types/mocha"
     ],
     "paths": {
+      "common/*": [
+        "../../../src/common/*"
+      ],
+      "browser/*": [
+        "../../../src/browser/*"
+      ],
       "@xterm/addon-progress": [
         "../typings/addon-progress.d.ts"
       ]

addons/addon-progress/test/tsconfig.json

@@ -10,6 +10,12 @@
     "sourceMap": true,
     "removeComments": true,
     "paths": {
+      "common/*": [
+        "../../../src/common/*"
+      ],
+      "browser/*": [
+        "../../../src/browser/*"
+      ],
       "*": [
         "./*"
       ]

addons/addon-progress/webpack.config.js

@@ -24,6 +24,11 @@ module.exports = {
   resolve: {
     modules: ['./node_modules'],
     extensions: [ '.js' ],
+    alias: {
+      common: path.resolve('../../out/common'),
+      browser: path.resolve('../../out/browser'),
+      vs: path.resolve('../../out/vs')
+    }
   },
   output: {
     filename: mainFile,