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/es-abstract/helpers/timeConstants.js

@@ -0,0 +1,19 @@
+'use strict';
+
+var HoursPerDay = 24;
+var MinutesPerHour = 60;
+var SecondsPerMinute = 60;
+var msPerSecond = 1e3;
+var msPerMinute = msPerSecond * SecondsPerMinute;
+var msPerHour = msPerMinute * MinutesPerHour;
+var msPerDay = 86400000;
+
+module.exports = {
+	HoursPerDay: HoursPerDay,
+	MinutesPerHour: MinutesPerHour,
+	SecondsPerMinute: SecondsPerMinute,
+	msPerSecond: msPerSecond,
+	msPerMinute: msPerMinute,
+	msPerHour: msPerHour,
+	msPerDay: msPerDay
+};