fix: use binary flags for timezone/locale instead of detectable CDP emulation

- Remove locale and timezone_id from Playwright context kwargs (CDP)
- Pass timezone via --fingerprint-timezone binary flag (process-wide)
- Pass locale via --lang + --fingerprint-locale binary flags
- Accept both timezone and timezone_id param names silently (no deprecation)
- Update all wrapper tests to verify binary args, not CDP context params

js/src/playwright.ts

@@ -11,10 +11,9 @@ import { ensureBinary } from "./download.js";
 import { parseProxyUrl } from "./proxy.js";
 import { maybeResolveGeoip } from "./geoip.js";
 
-/** @internal Migrate deprecated timezoneId → timezone, warn once. Exported for testing. */
-export function migrateTimezoneId<T extends { timezone?: string; timezoneId?: string }>(options: T): T {
+/** @internal Accept both timezone and timezoneId — either works, no warning. Exported for testing. */
+export function resolveTimezone<T extends { timezone?: string; timezoneId?: string }>(options: T): T {
   if (options.timezoneId != null) {
-    console.warn("[cloakbrowser] timezoneId is deprecated, use timezone instead");
     const merged = { ...options, timezone: options.timezone ?? options.timezoneId };
     delete (merged as any).timezoneId;
     return merged;
@@ -86,21 +85,19 @@ export async function launch(options: LaunchOptions = {}): Promise<Browser> {
 export async function launchContext(
   options: LaunchContextOptions = {}
 ): Promise<BrowserContext> {
-  options = migrateTimezoneId(options);
+  options = resolveTimezone(options);
   // Resolve geoip BEFORE launch() to avoid double-resolution
   const resolved = await maybeResolveGeoip(options);
-  // Skip --fingerprint-timezone binary flag: it only applies to the default
-  // context and interferes with Playwright's timezoneId on new contexts.
-  // Timezone is set via browser.newContext(timezoneId: ...) below instead.
-  const browser = await launch({ ...options, ...resolved, geoip: false, timezone: undefined });
+  // --fingerprint-timezone is process-wide (reads CommandLine in renderer),
+  // so it applies to ALL contexts, not just the default one.
+  // locale and timezone are set via binary flags only — no CDP emulation.
+  const browser = await launch({ ...options, ...resolved, geoip: false });
 
   let context: BrowserContext;
   try {
     context = await browser.newContext({
       ...(options.userAgent ? { userAgent: options.userAgent } : {}),
       viewport: options.viewport ?? DEFAULT_VIEWPORT,
-      ...(resolved.locale ? { locale: resolved.locale } : {}),
-      ...(resolved.timezone ? { timezoneId: resolved.timezone } : {}),
       ...(options.colorScheme ? { colorScheme: options.colorScheme } : {}),
     });
   } catch (err) {
@@ -153,13 +150,15 @@ export async function launchContext(
 export async function launchPersistentContext(
   options: LaunchPersistentContextOptions
 ): Promise<BrowserContext> {
-  options = migrateTimezoneId(options);
+  options = resolveTimezone(options);
   const { chromium } = await import("playwright-core");
 
   const binaryPath = process.env.CLOAKBROWSER_BINARY_PATH || (await ensureBinary());
   const resolved = await maybeResolveGeoip(options);
   const args = buildArgs({ ...options, ...resolved });
 
+  // locale and timezone are set via binary flags (--lang, --fingerprint-timezone)
+  // — NOT via Playwright context kwargs which use detectable CDP emulation.
   const context = await chromium.launchPersistentContext(options.userDataDir, {
     executablePath: binaryPath,
     headless: options.headless ?? true,
@@ -170,8 +169,6 @@ export async function launchPersistentContext(
       : {}),
     ...(options.userAgent ? { userAgent: options.userAgent } : {}),
     viewport: options.viewport ?? DEFAULT_VIEWPORT,
-    ...(resolved.locale ? { locale: resolved.locale } : {}),
-    ...(resolved.timezone ? { timezoneId: resolved.timezone } : {}),
     ...(options.colorScheme ? { colorScheme: options.colorScheme } : {}),
     ...options.launchOptions,
   });