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/@babel/eslint-parser/lib/utils/eslint-version.cjs

@@ -0,0 +1,5 @@
+"use strict";
+
+module.exports = parseInt(require("eslint/package.json").version, 10);
+
+//# sourceMappingURL=eslint-version.cjs.map

node_modules/@babel/eslint-parser/lib/utils/eslint-version.cjs.map

@@ -0,0 +1 @@
+{"version":3,"names":["parseInt","require","version"],"sources":["../../src/utils/eslint-version.cts"],"sourcesContent":["export = parseInt(require(\"eslint/package.json\").version, 10);\n"],"mappings":";;iBAASA,QAAQ,CAACC,OAAO,CAAC,qBAAqB,CAAC,CAACC,OAAO,EAAE,EAAE,CAAC","ignoreList":[]}