chore: update tailwind to v4

As is customary in the JS world EVERYTHING must break with each major version

frontend/postcss.config.js

@@ -1,12 +1,3 @@
-const postcssPresetEnv = require("postcss-preset-env");
-const tailwindcss = require('tailwindcss');
-
 module.exports = {
-    plugins: [postcssPresetEnv({
-        /* use stage 2 features + disable logical properties and values rule */
-        stage: 2,
-        features: {
-            'logical-properties-and-values': false
-        }
-    }), tailwindcss],
+    plugins: {"@tailwindcss/postcss": {}},
 };