fix: React upgrade Deprecation fixes

Author: camd

.vscode/settings.json

@@ -1,5 +1,10 @@
 {
-  "chat.mcp.discovery.enabled": true,
+  "chat.mcp.discovery.enabled": {
+    "claude-desktop": true,
+    "windsurf": true,
+    "cursor-global": true,
+    "cursor-workspace": true
+  },
   "editor.formatOnSave": true,
   "editor.defaultFormatter": "esbenp.prettier-vscode",
   "[javascript]": {

babel.config.json

@@ -25,12 +25,16 @@
   ],
   "plugins": [
     "@babel/plugin-syntax-dynamic-import",
-    "react-hot-loader/babel",
     [
       "@babel/plugin-proposal-class-properties",
       {
         "loose": true
       }
     ]
-  ]
+  ],
+  "env": {
+    "development": {
+      "plugins": ["react-refresh/babel"]
+    }
+  }
 }

docs/deprecation-warnings.md

@@ -0,0 +1,49 @@
+# Known Deprecation Warnings
+
+## DEP0060: util._extend Deprecation Warning
+
+When running the frontend development server with `yarn start:stage`, you may encounter the following deprecation warning:
+
+```code
+(node:xxxxx) [DEP0060] DeprecationWarning: The `util._extend` API is deprecated. Please use Object.assign() instead.
+    at ProxyServer.<anonymous> (/Users/.../node_modules/http-proxy/lib/http-proxy/index.js:50:26)
+    at HttpProxyMiddleware.middleware (/Users/.../node_modules/http-proxy-middleware/dist/http-proxy-middleware.js:22:32)
+```
+
+### What causes this warning?
+
+This warning originates from the `[email protected]` library, which is a transitive dependency used by:
+
+- `[email protected]` (our dev dependency)
+- `[email protected]` (dependency of webpack-dev-server)
+
+The `http-proxy` library still uses the deprecated `util._extend()` API instead of the modern `Object.assign()`.
+
+### Is this harmful?
+
+**No, this warning is completely harmless:**
+
+- The functionality works exactly the same
+- `util._extend()` still functions correctly in all supported Node.js versions
+- This is purely a deprecation notice, not an error
+- It does not affect the application's functionality or performance
+
+### When will this be fixed?
+
+This will be resolved when:
+
+1. The upstream `http-proxy` library is updated to use `Object.assign()` instead of `util._extend()`
+2. OR when `webpack-dev-server` switches to a different proxy implementation
+3. OR when we upgrade to newer versions that have resolved this issue
+
+### React 19 Compatibility
+
+This deprecation warning will not prevent upgrading to React 19 or any future React versions, as it's unrelated to React and only affects the development server's proxy functionality.
+
+### Alternative Solutions Considered
+
+1. **Patching the library**: We could patch `http-proxy` to use `Object.assign()`, but this adds maintenance overhead
+2. **Suppressing warnings**: We could use `NODE_OPTIONS='--no-deprecation'` to hide all deprecation warnings, but this might hide other important warnings
+3. **Yarn resolutions**: We could try to force a different version, but `1.18.1` is already the latest
+
+For now, we've decided to leave the warning visible as it's informational and doesn't impact functionality.