[XDebug] Add a mock @php-wasm/xdebug-bridge package (#2398)

## Motivation for the change, related issues

Adds a mock, AI-generated `@php-wasm/xdebug-bridge` package to jumpstart
the work on [XDebug in browser
devtools](#2288).

Cursor prompt:

> Create a new package `@php-wasm/xdebug-bridge` with a
startXDebugBridge() function that starts a plain network server, It
should accept a few config params via an object, e.g. protocol ("cdp"),
xdebugServerPort (number, default to xdebug default port).
> 
> It should also ship a CLI script that can be used to run that function
from CLI. Accept CLI args, print useful information, but make sure
startXDebugBridge() can still be executed without printing anything to
console.

## Testing Instructions (or ideally a Blueprint)

Confirm it doesn't break the CI.

cc @mho22

Author: adamziel

package-lock.json

@@ -0,0 +1,18 @@
+{
+	"extends": ["../../../.eslintrc.json"],
+	"ignorePatterns": ["!**/*"],
+	"overrides": [
+		{
+			"files": ["*.ts", "*.tsx", "*.js", "*.jsx"],
+			"rules": {}
+		},
+		{
+			"files": ["*.ts", "*.tsx"],
+			"rules": {}
+		},
+		{
+			"files": ["*.js", "*.jsx"],
+			"rules": {}
+		}
+	]
+} 

packages/php-wasm/xdebug-bridge/.eslintrc.json

@@ -0,0 +1,70 @@
+# @php-wasm/xdebug-bridge
+
+XDebug bridge server for PHP.wasm that enables debugging connections between XDebug and debugging clients.
+
+## Installation
+
+```bash
+npm install @php-wasm/xdebug-bridge
+```
+
+## Usage
+
+### Programmatic API
+
+```typescript
+import { startXDebugBridge } from '@php-wasm/xdebug-bridge';
+
+// Start with default settings
+const server = startXDebugBridge();
+await server.start();
+
+// Start with custom configuration
+const server = startXDebugBridge({
+  protocol: 'cdp',           // or 'dap'
+  xdebugServerPort: 9003,    // XDebug connection port
+  xdebugServerHost: 'localhost',
+  verbose: false,            // Silent mode
+});
+
+await server.start();
+
+// Stop the server
+await server.stop();
+```
+
+### CLI Usage
+
+```bash
+# Start with default settings
+npx xdebug-bridge
+
+# Custom port and verbose logging
+npx xdebug-bridge --port 9000 --verbose
+
+# DAP protocol, bind to all interfaces
+npx xdebug-bridge --protocol dap --host 0.0.0.0
+
+# Show help
+npx xdebug-bridge --help
+```
+
+## Configuration Options
+
+- `protocol`: Protocol to use ('cdp' or 'dap', default: 'cdp')
+- `xdebugServerPort`: Port to listen for XDebug connections (default: 9003)
+- `xdebugServerHost`: Host to bind to (default: 'localhost')
+- `verbose`: Enable verbose logging (default: false for API, true for CLI)
+- `logger`: Custom logger function
+
+## Events
+
+The server emits events for monitoring connection activity:
+
+- `started`: Server has started
+- `stopped`: Server has stopped
+- `connection`: New XDebug connection established
+- `disconnection`: XDebug connection closed
+- `xdebugData`: Raw XDebug data received
+- `error`: Server error occurred
+- `socketError`: Socket-level error occurred 

packages/php-wasm/xdebug-bridge/README.md

@@ -0,0 +1,47 @@
+{
+	"name": "@php-wasm/xdebug-bridge",
+	"version": "1.2.3",
+	"description": "XDebug bridge server for PHP.wasm",
+	"repository": {
+		"type": "git",
+		"url": "https://github.com/WordPress/wordpress-playground"
+	},
+	"homepage": "https://developer.wordpress.org/playground",
+	"author": "The WordPress contributors",
+	"contributors": [
+		{
+			"name": "Adam Zielinski",
+			"email": "[email protected]",
+			"url": "https://github.com/adamziel"
+		}
+	],
+	"exports": {
+		".": {
+			"import": "./index.js",
+			"require": "./index.cjs"
+		},
+		"./package.json": "./package.json",
+		"./README.md": "./README.md"
+	},
+	"type": "module",
+	"main": "./index.cjs",
+	"module": "./index.js",
+	"bin": "cli.js",
+	"typedoc": {
+		"entryPoint": "./src/index.ts",
+		"readmeFile": "./README.md",
+		"displayName": "@php-wasm/xdebug-bridge",
+		"tsconfig": "./tsconfig.lib.json"
+	},
+	"publishConfig": {
+		"access": "public",
+		"directory": "../../../dist/packages/php-wasm/xdebug-bridge"
+	},
+	"license": "GPL-2.0-or-later",
+	"types": "index.d.ts",
+	"gitHead": "2f8d8f3cea548fbd75111e8659a92f601cddc593",
+	"engines": {
+		"node": ">=20.18.3",
+		"npm": ">=10.1.0"
+	}
+} 

packages/php-wasm/xdebug-bridge/package.json

@@ -0,0 +1,71 @@
+{
+	"name": "php-wasm-xdebug-bridge",
+	"$schema": "../../../node_modules/nx/schemas/project-schema.json",
+	"sourceRoot": "packages/php-wasm/xdebug-bridge/src",
+	"projectType": "library",
+	"targets": {
+		"build": {
+			"executor": "nx:noop",
+			"dependsOn": ["build:README"]
+		},
+		"build:README": {
+			"executor": "nx:run-commands",
+			"options": {
+				"commands": [
+					"cp packages/php-wasm/xdebug-bridge/README.md dist/packages/php-wasm/xdebug-bridge"
+				]
+			},
+			"dependsOn": ["build:package-json"]
+		},
+		"build:package-json": {
+			"executor": "@wp-playground/nx-extensions:package-json",
+			"options": {
+				"tsConfig": "packages/php-wasm/xdebug-bridge/tsconfig.lib.json",
+				"outputPath": "dist/packages/php-wasm/xdebug-bridge",
+				"buildTarget": "php-wasm-xdebug-bridge:build:bundle:production"
+			}
+		},
+		"build:bundle": {
+			"executor": "@nx/vite:build",
+			"outputs": ["{options.outputPath}"],
+			"options": {
+				"main": "dist/packages/php-wasm/xdebug-bridge/index.js",
+				"outputPath": "dist/packages/php-wasm/xdebug-bridge"
+			},
+			"defaultConfiguration": "production",
+			"configurations": {
+				"development": {
+					"minify": false
+				},
+				"production": {
+					"minify": true
+				}
+			}
+		},
+		"dev": {
+			"executor": "nx:run-commands",
+			"options": {
+				"command": "bun --watch ./packages/php-wasm/xdebug-bridge/src/cli.ts",
+				"tty": true
+			}
+		},
+		"test": {
+			"executor": "@nx/vite:test",
+			"outputs": [
+				"{workspaceRoot}/coverage/packages/php-wasm/xdebug-bridge"
+			],
+			"options": {
+				"reportsDirectory": "../../../coverage/packages/php-wasm/xdebug-bridge",
+				"testFiles": ["tests/mock-test.spec.ts"]
+			}
+		},
+		"lint": {
+			"executor": "@nx/eslint:lint",
+			"outputs": ["{options.outputFile}"],
+			"options": {
+				"lintFilePatterns": ["packages/php-wasm/xdebug-bridge/**/*.ts"]
+			}
+		}
+	},
+	"tags": ["php-wasm"]
+}