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/fork-ts-checker-webpack-plugin/lib/rpc/error/RpcMessagePortClosedError.d.ts

@@ -0,0 +1,3 @@
+declare class RpcMessagePortClosedError extends Error {
+}
+export { RpcMessagePortClosedError };

node_modules/fork-ts-checker-webpack-plugin/lib/rpc/error/RpcMessagePortClosedError.js

@@ -0,0 +1,5 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+class RpcMessagePortClosedError extends Error {
+}
+exports.RpcMessagePortClosedError = RpcMessagePortClosedError;

node_modules/fork-ts-checker-webpack-plugin/lib/rpc/error/RpcRemoteError.d.ts

@@ -0,0 +1,6 @@
+declare class RpcRemoteError extends Error {
+    readonly stack?: string | undefined;
+    constructor(message: string, stack?: string | undefined);
+    toString(): string;
+}
+export { RpcRemoteError };

node_modules/fork-ts-checker-webpack-plugin/lib/rpc/error/RpcRemoteError.js

@@ -0,0 +1,17 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+class RpcRemoteError extends Error {
+    constructor(message, stack) {
+        super(message);
+        this.stack = stack;
+    }
+    toString() {
+        if (this.stack) {
+            return [this.message, this.stack].join('\n');
+        }
+        else {
+            return this.message;
+        }
+    }
+}
+exports.RpcRemoteError = RpcRemoteError;