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/ajv-keywords/keywords/allRequired.js

@@ -0,0 +1,18 @@
+'use strict';
+
+module.exports = function defFunc(ajv) {
+  defFunc.definition = {
+    type: 'object',
+    macro: function (schema, parentSchema) {
+      if (!schema) return true;
+      var properties = Object.keys(parentSchema.properties);
+      if (properties.length == 0) return true;
+      return {required: properties};
+    },
+    metaSchema: {type: 'boolean'},
+    dependencies: ['properties']
+  };
+
+  ajv.addKeyword('allRequired', defFunc.definition);
+  return ajv;
+};