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/lucide-react/dist/esm/icons/split-square-vertical.mjs

@@ -0,0 +1,14 @@
+/**
+ * lucide-react v0.0.1 - ISC
+ */
+
+import createLucideIcon from '../createLucideIcon.mjs';
+
+const SplitSquareVertical = createLucideIcon("SplitSquareVertical", [
+  ["path", { d: "M5 8V5c0-1 1-2 2-2h10c1 0 2 1 2 2v3", key: "1pi83i" }],
+  ["path", { d: "M19 16v3c0 1-1 2-2 2H7c-1 0-2-1-2-2v-3", key: "ido5k7" }],
+  ["line", { x1: "4", x2: "20", y1: "12", y2: "12", key: "1e0a9i" }]
+]);
+
+export { SplitSquareVertical as default };
+//# sourceMappingURL=split-square-vertical.mjs.map