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/yaml/dist/legacy-exports.js

@@ -0,0 +1,16 @@
+'use strict';
+
+var warnings = require('./warnings-1000a372.js');
+require('./PlainValue-ec8e588e.js');
+require('./resolveSeq-d03cb037.js');
+
+
+
+exports.binary = warnings.binary;
+exports.floatTime = warnings.floatTime;
+exports.intTime = warnings.intTime;
+exports.omap = warnings.omap;
+exports.pairs = warnings.pairs;
+exports.set = warnings.set;
+exports.timestamp = warnings.timestamp;
+exports.warnFileDeprecation = warnings.warnFileDeprecation;