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/aria-query/lib/etc/roles/literal/spinbuttonRole.js

@@ -0,0 +1,39 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var spinbuttonRole = {
+  abstract: false,
+  accessibleNameRequired: true,
+  baseConcepts: [],
+  childrenPresentational: false,
+  nameFrom: ['author'],
+  prohibitedProps: [],
+  props: {
+    'aria-errormessage': null,
+    'aria-invalid': null,
+    'aria-readonly': null,
+    'aria-required': null,
+    'aria-valuetext': null,
+    'aria-valuenow': '0'
+  },
+  relatedConcepts: [{
+    concept: {
+      attributes: [{
+        name: 'type',
+        value: 'number'
+      }],
+      name: 'input'
+    },
+    module: 'HTML'
+  }],
+  requireContextRole: [],
+  requiredContextRole: [],
+  requiredOwnedElements: [],
+  requiredProps: {},
+  superClass: [['roletype', 'widget', 'composite'], ['roletype', 'widget', 'input'], ['roletype', 'structure', 'range']]
+};
+var _default = spinbuttonRole;
+exports.default = _default;