feat: add JavaScript/TypeScript wrapper with Playwright + Puppeteer support

Adds js/ package mirroring the Python wrapper architecture:
- Dual API: import from 'cloakbrowser' (Playwright) or 'cloakbrowser/puppeteer'
- TypeScript with full type definitions
- Same binary download/cache logic, same stealth args, same env vars
- Optional peer deps: users install only the runtime they need
- Full 6-site stealth test suite (sannysoft, incolumitas, BrowserScan, deviceandbrowserinfo, FingerprintJS, reCAPTCHA v3)
- Published to npm as cloakbrowser@0.1.2

js/src/playwright.ts

@@ -0,0 +1,99 @@
+/**
+ * Playwright launch wrapper for cloakbrowser.
+ * Mirrors Python cloakbrowser/browser.py.
+ */
+
+import type { Browser, BrowserContext } from "playwright-core";
+import type { LaunchOptions, LaunchContextOptions } from "./types.js";
+import { getDefaultStealthArgs } from "./config.js";
+import { ensureBinary } from "./download.js";
+
+/**
+ * Launch stealth Chromium browser via Playwright.
+ *
+ * @example
+ * ```ts
+ * import { launch } from 'cloakbrowser';
+ * const browser = await launch();
+ * const page = await browser.newPage();
+ * await page.goto('https://bot.incolumitas.com');
+ * console.log(await page.title());
+ * await browser.close();
+ * ```
+ */
+export async function launch(options: LaunchOptions = {}): Promise<Browser> {
+  const { chromium } = await import("playwright-core");
+
+  const binaryPath = process.env.CLOAKBROWSER_BINARY_PATH || (await ensureBinary());
+  const args = buildArgs(options);
+
+  const browser = await chromium.launch({
+    executablePath: binaryPath,
+    headless: options.headless ?? true,
+    args,
+    ignoreDefaultArgs: ["--enable-automation"],
+    ...(options.proxy ? { proxy: { server: options.proxy } } : {}),
+    ...options.launchOptions,
+  });
+
+  return browser;
+}
+
+/**
+ * Launch stealth browser and return a BrowserContext with common options pre-set.
+ * Closing the context also closes the browser.
+ *
+ * @example
+ * ```ts
+ * import { launchContext } from 'cloakbrowser';
+ * const context = await launchContext({
+ *   userAgent: 'Mozilla/5.0...',
+ *   viewport: { width: 1920, height: 1080 },
+ * });
+ * const page = await context.newPage();
+ * await page.goto('https://example.com');
+ * await context.close(); // also closes browser
+ * ```
+ */
+export async function launchContext(
+  options: LaunchContextOptions = {}
+): Promise<BrowserContext> {
+  const browser = await launch(options);
+
+  let context: BrowserContext;
+  try {
+    context = await browser.newContext({
+      ...(options.userAgent ? { userAgent: options.userAgent } : {}),
+      ...(options.viewport ? { viewport: options.viewport } : {}),
+      ...(options.locale ? { locale: options.locale } : {}),
+      ...(options.timezoneId ? { timezoneId: options.timezoneId } : {}),
+    });
+  } catch (err) {
+    await browser.close();
+    throw err;
+  }
+
+  // Patch close() to also close the browser
+  const origClose = context.close.bind(context);
+  context.close = async () => {
+    await origClose();
+    await browser.close();
+  };
+
+  return context;
+}
+
+// ---------------------------------------------------------------------------
+// Internal
+// ---------------------------------------------------------------------------
+
+function buildArgs(options: LaunchOptions): string[] {
+  const args: string[] = [];
+  if (options.stealthArgs !== false) {
+    args.push(...getDefaultStealthArgs());
+  }
+  if (options.args) {
+    args.push(...options.args);
+  }
+  return args;
+}