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/autoprefixer/lib/hacks/flex-wrap.js

@@ -0,0 +1,19 @@
+let Declaration = require('../declaration')
+let flexSpec = require('./flex-spec')
+
+class FlexWrap extends Declaration {
+  /**
+   * Don't add prefix for 2009 spec
+   */
+  set(decl, prefix) {
+    let spec = flexSpec(prefix)[0]
+    if (spec !== 2009) {
+      return super.set(decl, prefix)
+    }
+    return undefined
+  }
+}
+
+FlexWrap.names = ['flex-wrap']
+
+module.exports = FlexWrap