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/arrow-left-square.mjs

@@ -0,0 +1,17 @@
+/**
+ * lucide-react v0.0.1 - ISC
+ */
+
+import createLucideIcon from '../createLucideIcon.mjs';
+
+const ArrowLeftSquare = createLucideIcon("ArrowLeftSquare", [
+  [
+    "rect",
+    { width: "18", height: "18", x: "3", y: "3", rx: "2", key: "afitv7" }
+  ],
+  ["path", { d: "m12 8-4 4 4 4", key: "15vm53" }],
+  ["path", { d: "M16 12H8", key: "1fr5h0" }]
+]);
+
+export { ArrowLeftSquare as default };
+//# sourceMappingURL=arrow-left-square.mjs.map