chore: refine review-comment fixes

- Default disableBrowserSandbox to false; only containerized and logLevel
  remain optional (their undefined value carries runtime semantics).
- Inline the serviceLocator mention into the existing getGlobalConfig
  paragraph instead of appending a separate one.

Author: B4nan

docs/guides/configuration.mdx

@@ -137,9 +137,7 @@ The last option to adjust Crawlee configuration is to use the <ApiLink to="core/
 
 ### Global Configuration
 
-By default, there is a global singleton instance of `Configuration` class, it is used by the crawlers and some other classes that depend on a configurable behavior. In most cases you don't need to adjust any options there, but if needed - you can get access to it via <ApiLink to="core/class/Configuration#getGlobalConfig">`Configuration.getGlobalConfig()`</ApiLink> function. Configuration values are accessible directly as properties.
-
-Under the hood, `Configuration.getGlobalConfig()` delegates to <ApiLink to="core/class/ServiceLocator">`serviceLocator`</ApiLink>, which is the single source of truth for Crawlee's shared services (configuration, event manager, storage client, logger). You can access the same instance via `serviceLocator.getConfiguration()` and swap services globally with `serviceLocator.setConfiguration(...)` before any crawler is created.
+By default, there is a global singleton instance of `Configuration` class, it is used by the crawlers and some other classes that depend on a configurable behavior. In most cases you don't need to adjust any options there, but if needed - you can access it via <ApiLink to="core/class/Configuration#getGlobalConfig">`Configuration.getGlobalConfig()`</ApiLink>, which delegates to the global <ApiLink to="core/class/ServiceLocator">`serviceLocator`</ApiLink> — the single source of truth for Crawlee's shared services (configuration, event manager, storage client, logger). You can also reach the same instance directly via `serviceLocator.getConfiguration()` or swap services globally with `serviceLocator.setConfiguration(...)` before any crawler is created. Configuration values are accessible directly as properties on the instance.
 
 ```js
 import { CheerioCrawler, Configuration, sleep } from 'crawlee';

packages/core/src/configuration.ts

@@ -76,7 +76,8 @@ export const crawleeConfigFields = {
     xvfb: field(coerceBoolean.default(false), 'CRAWLEE_XVFB'),
     chromeExecutablePath: field(z.string().optional(), 'CRAWLEE_CHROME_EXECUTABLE_PATH'),
     defaultBrowserPath: field(z.string().optional(), 'CRAWLEE_DEFAULT_BROWSER_PATH'),
-    disableBrowserSandbox: field(coerceBoolean.optional(), 'CRAWLEE_DISABLE_BROWSER_SANDBOX'),
+    /** @default false */
+    disableBrowserSandbox: field(coerceBoolean.default(false), 'CRAWLEE_DISABLE_BROWSER_SANDBOX'),
     logLevel: field(logLevelSchema.optional(), 'CRAWLEE_LOG_LEVEL'),
     /** @default true */
     persistStorage: field(coerceBoolean.default(true), 'CRAWLEE_PERSIST_STORAGE'),

packages/core/test/core/configuration.test.ts

@@ -41,6 +41,7 @@ describe('Configuration', () => {
             expect(config.inputKey).toBe('INPUT');
             expect(config.headless).toBe(true);
             expect(config.xvfb).toBe(false);
+            expect(config.disableBrowserSandbox).toBe(false);
             expect(config.purgeOnStart).toBe(true);
             expect(config.persistStorage).toBe(true);
             expect(config.maxUsedCpuRatio).toBe(0.95);
@@ -49,11 +50,7 @@ describe('Configuration', () => {
             expect(config.systemInfoIntervalMillis).toBe(1_000);
         });
 
-        // `disableBrowserSandbox`, `containerized`, and `logLevel` are intentionally optional
-        // (no default) — `undefined` is a meaningful signal for each:
-        //   - `disableBrowserSandbox`: only a boolean check is done at the call site, so `undefined`
-        //     behaves the same as `false` and leaves room to distinguish "unset" from "explicitly false"
-        //     if callers ever need to.
+        // `containerized` and `logLevel` are intentionally optional — `undefined` is a meaningful signal:
         //   - `containerized`: consumers fall back to runtime detection via `isContainerized()` using
         //     `config.containerized ?? (await isContainerized())`; defaulting to `false` would disable
         //     auto-detection.
@@ -64,7 +61,6 @@ describe('Configuration', () => {
             expect(config.memoryMbytes).toBeUndefined();
             expect(config.chromeExecutablePath).toBeUndefined();
             expect(config.defaultBrowserPath).toBeUndefined();
-            expect(config.disableBrowserSandbox).toBeUndefined();
             expect(config.containerized).toBeUndefined();
             expect(config.logLevel).toBeUndefined();
         });