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/prompts/lib/dateparts/year.js

@@ -0,0 +1,28 @@
+'use strict';
+
+const DatePart = require('./datepart');
+
+class Year extends DatePart {
+  constructor(opts={}) {
+    super(opts);
+  }
+
+  up() {
+    this.date.setFullYear(this.date.getFullYear() + 1);
+  }
+
+  down() {
+    this.date.setFullYear(this.date.getFullYear() - 1);
+  }
+
+  setTo(val) {
+    this.date.setFullYear(val.substr(-4));
+  }
+
+  toString() {
+    let year = String(this.date.getFullYear()).padStart(4, '0');
+    return this.token.length === 2 ? year.substr(-2) : year;
+  }
+}
+
+module.exports = Year;