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/mail-open.mjs

@@ -0,0 +1,19 @@
+/**
+ * lucide-react v0.0.1 - ISC
+ */
+
+import createLucideIcon from '../createLucideIcon.mjs';
+
+const MailOpen = createLucideIcon("MailOpen", [
+  [
+    "path",
+    {
+      d: "M21.2 8.4c.5.38.8.97.8 1.6v10a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V10a2 2 0 0 1 .8-1.6l8-6a2 2 0 0 1 2.4 0l8 6Z",
+      key: "1jhwl8"
+    }
+  ],
+  ["path", { d: "m22 10-8.97 5.7a1.94 1.94 0 0 1-2.06 0L2 10", key: "1qfld7" }]
+]);
+
+export { MailOpen as default };
+//# sourceMappingURL=mail-open.mjs.map