Initial commit: Developer Tools MVP with visual editor

- Complete React app with 7 developer tools
- JSON Tool with visual structured editor
- Serialize Tool with visual structured editor
- URL, Base64, CSV/JSON, Beautifier, Diff tools
- Responsive navigation with dropdown menu
- Dark/light mode toggle
- Mobile-responsive design with sticky header
- All tools working with copy/paste functionality

node_modules/jest-jasmine2/build/setup_jest_globals.d.ts

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+import type { Config } from '@jest/types';
+import { SnapshotStateType } from 'jest-snapshot';
+import type { Plugin } from 'pretty-format';
+export declare type SetupOptions = {
+    config: Config.ProjectConfig;
+    globalConfig: Config.GlobalConfig;
+    localRequire: (moduleName: string) => Plugin;
+    testPath: Config.Path;
+};
+export default function setupJestGlobals({ config, globalConfig, localRequire, testPath, }: SetupOptions): Promise<SnapshotStateType>;