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/tsconfig-paths/lib/index.d.ts

@@ -0,0 +1,5 @@
+export { createMatchPath, matchFromAbsolutePaths, MatchPath, } from "./match-path-sync";
+export { createMatchPathAsync, matchFromAbsolutePathsAsync, MatchPathAsync, } from "./match-path-async";
+export { register } from "./register";
+export { loadConfig, ConfigLoaderResult, ConfigLoaderSuccessResult, ConfigLoaderFailResult, } from "./config-loader";
+export { ReadJsonSync, ReadJsonAsync, FileExistsSync, FileExistsAsync, } from "./filesystem";