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/headless/Terminal.ts

@@ -21,11 +21,11 @@
  *   http://linux.die.net/man/7/urxvt
  */
 
-import { DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
-import { IBuffer } from 'common/buffer/Types';
-import { CoreTerminal } from 'common/CoreTerminal';
-import { IMarker, ITerminalOptions } from 'common/Types';
-import { Emitter, EventUtils } from 'common/Event';
+import { DEFAULT_ATTR_DATA } from '../common/buffer/BufferLine';
+import { IBuffer } from '../common/buffer/Types';
+import { CoreTerminal } from '../common/CoreTerminal';
+import { IMarker, ITerminalOptions } from '../common/Types';
+import { Emitter, EventUtils } from '../common/Event';
 
 export class Terminal extends CoreTerminal {
   private readonly _onBell = this._register(new Emitter<void>());

src/headless/public/Terminal.test.ts

@@ -4,7 +4,7 @@
  */
 
 import { deepStrictEqual, strictEqual, throws } from 'assert';
-import { Terminal } from 'headless/public/Terminal';
+import { Terminal } from './Terminal';
 import { ITerminalOptions } from '@xterm/headless';
 
 let term: Terminal;

src/headless/public/Terminal.ts

@@ -3,15 +3,15 @@
  * @license MIT
  */
 
-import { BufferNamespaceApi } from 'common/public/BufferNamespaceApi';
-import { ParserApi } from 'common/public/ParserApi';
-import { UnicodeApi } from 'common/public/UnicodeApi';
+import { BufferNamespaceApi } from '../../common/public/BufferNamespaceApi';
+import { ParserApi } from '../../common/public/ParserApi';
+import { UnicodeApi } from '../../common/public/UnicodeApi';
 import { IBufferNamespace as IBufferNamespaceApi, IMarker, IModes, IParser, ITerminalAddon, ITerminalInitOnlyOptions, IUnicodeHandling, Terminal as ITerminalApi } from '@xterm/headless';
-import { Terminal as TerminalCore } from 'headless/Terminal';
-import { AddonManager } from 'common/public/AddonManager';
-import { ITerminalOptions } from 'common/Types';
-import { Disposable } from 'common/Lifecycle';
-import type { IEvent } from 'common/Event';
+import { Terminal as TerminalCore } from '../Terminal';
+import { AddonManager } from '../../common/public/AddonManager';
+import { ITerminalOptions } from '../../common/Types';
+import { Disposable } from '../../common/Lifecycle';
+import type { IEvent } from '../../common/Event';
 /**
  * The set of options that only have an effect when set in the Terminal constructor.
  */

src/headless/tsconfig.json

@@ -10,11 +10,7 @@
     "types": [
       "../../node_modules/@types/mocha",
       "../../node_modules/@types/node"
-    ],
-    "paths": {
-      "common/*": [ "./../common/*" ],
-      "*": [ "./../*" ]
-    }
+    ]
   },
   "include": [
     "./**/*",