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/adjust-sourcemap-loader/codec/utility/get-context-directory.js

@@ -0,0 +1,17 @@
+'use strict';
+
+var path = require('path');
+
+/**
+ * Infer the compilation context directory from options.
+ * Relative paths are resolved against process.cwd().
+ * @this {{options: object}} A loader or compilation
+ * @returns {string} process.cwd() where not defined else the output path string
+ */
+function getContextDirectory() {
+  /* jshint validthis:true */
+  var context = this.options ? this.options.context : null;
+  return !!context && path.resolve(context) || process.cwd();
+}
+
+module.exports = getContextDirectory;