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/fork-ts-checker-webpack-plugin/lib/issue/IssueSeverity.js

@@ -0,0 +1,11 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+function isIssueSeverity(value) {
+    return ['error', 'warning'].includes(value);
+}
+exports.isIssueSeverity = isIssueSeverity;
+function compareIssueSeverities(severityA, severityB) {
+    const [priorityA, priorityB] = [severityA, severityB].map((severity) => ['warning' /* 0 */, 'error' /* 1 */].indexOf(severity));
+    return Math.sign(priorityB - priorityA);
+}
+exports.compareIssueSeverities = compareIssueSeverities;