Fix _css undefined error by replacing babel-plugin-emotion with @emotion/babel-plugin

babel-plugin-emotion v10 is incompatible with @babel/helper-module-imports v7.28+,
causing css/cx imports to be silently dropped from compiled output. Switch to
@emotion/babel-plugin v11 which properly handles @emotion/css imports.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: LaurentClaes

babel.config.js

@@ -19,9 +19,9 @@ module.exports = function(api) {
   ];
 
   const plugins = [
-    ...(isTest ? [] : [['babel-plugin-emotion', {
+    ...(isTest ? [] : [['@emotion/babel-plugin', {
       sourceMap: false,
-      autoLabel: true,
+      autoLabel: 'dev-only',
       labelFormat: '[filename]__[local]',
     }]]),
     ...(isTest ? [] : ['babel-plugin-codegen']),

package-lock.json

@@ -62,6 +62,7 @@
     "@drawbotics/check-env": "^3.0.0",
     "@drawbotics/s3sync": "^1.0.1",
     "@drawbotics/use-screen-size": "^3.0.1",
+    "@emotion/babel-plugin": "^11.13.5",
     "@emotion/core": "^10.0.21",
     "@emotion/jest": "^11.14.0",
     "@mdx-js/loader": "^1.6.21",
@@ -86,8 +87,8 @@
     "chalk": "^2.4.2",
     "chokidar-cli": "^2.1.0",
     "concurrently": "^9.0.0",
-    "core-js": "^3.0.0",
     "copy-webpack-plugin": "^14.0.0",
+    "core-js": "^3.0.0",
     "css-loader": "^7.0.0",
     "emotion": "10.0.27",
     "empty-module": "^0.0.2",