refactor: switch to Tailwind v4 Vite plugin

- Replace @tailwindcss/postcss with @tailwindcss/vite
- Remove postcss.config.js
- Update vite.config.ts with tailwindcss plugin
- Remove @config directive from App.css (Vite plugin reads config automatically)

Author: afonsojramos

package.json

@@ -58,7 +58,7 @@
     "@graphql-codegen/schema-ast": "5.0.0",
     "@octokit/openapi-types": "27.0.0",
     "@parcel/watcher": "2.5.1",
-    "@tailwindcss/postcss": "4.1.18",
+    "@tailwindcss/vite": "^4.1.18",
     "@tauri-apps/cli": "^2",
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "16.3.1",

pnpm-lock.yaml

@@ -4,9 +4,6 @@
 /** GitHub Primer Design System */
 @import "@primer/css/dist/primer.css";
 
-/** Tailwind CSS Configuration */
-@config "../tailwind.config.ts";
-
 html,
 body,
 #root {

postcss.config.js

@@ -1,3 +1,4 @@
+import tailwindcss from '@tailwindcss/vite';
 import react from '@vitejs/plugin-react';
 import { defineConfig } from 'vite';
 
@@ -6,7 +7,7 @@ const host = process.env.TAURI_DEV_HOST;
 
 // https://vite.dev/config/
 export default defineConfig(async () => ({
-  plugins: [react()],
+  plugins: [react(), tailwindcss()],
 
   // Vite options tailored for Tauri development and only applied in `tauri dev` or `tauri build`
   //