fix(ui): restore Tailwind v4 @theme tokens + disable /register route (invite-only)

- Restore app.css with Tailwind v4 @import and @theme design tokens (Breeze had overwritten with v3 directives)
- Add @tailwindcss/vite tailwindcss() plugin back to vite.config.js
- Upgrade tailwindcss in package.json from ^3.1.0 to ^4.0.0; remove @tailwindcss/forms and autoprefixer (v3-only)
- Delete postcss.config.js (v3 PostCSS plugin, not needed for v4 Vite plugin)
- Comment out Volt::route('register', ...) in routes/auth.php — platform is invite-only
- Update RegistrationTest to assert /register returns 404 instead of 200

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

package.json

@@ -7,13 +7,10 @@
         "dev": "vite"
     },
     "devDependencies": {
-        "@tailwindcss/forms": "^0.5.2",
         "@tailwindcss/vite": "^4.0.0",
-        "autoprefixer": "^10.4.2",
         "concurrently": "^9.0.1",
         "laravel-vite-plugin": "^3.1",
-        "postcss": "^8.4.31",
-        "tailwindcss": "^3.1.0",
+        "tailwindcss": "^4.0.0",
         "vite": "^8.0.0",
         "vite-plugin-pwa": "^1.3.0"
     }

postcss.config.js

@@ -1,6 +0,0 @@
-export default {
-    plugins: {
-        tailwindcss: {},
-        autoprefixer: {},
-    },
-};

resources/css/app.css

@@ -1,3 +1,33 @@
-@tailwind base;
-@tailwind components;
-@tailwind utilities;
+@import "tailwindcss";
+
+@theme {
+  --color-bg-base:        #f0eee9;
+  --color-text-primary:   oklch(0.22 0.015 270);
+  --color-text-secondary: oklch(0.42 0.012 270);
+  --color-text-muted:     oklch(0.58 0.01 270);
+  --color-border-subtle:  oklch(0.92 0.006 85);
+  --font-display: 'Plus Jakarta Sans', sans-serif;
+  --font-mono:    'JetBrains Mono', monospace;
+}
+
+@font-face {
+    font-family: 'Plus Jakarta Sans';
+    src: url('/fonts/PlusJakartaSans-VariableFont_wght.woff2') format('woff2');
+    font-weight: 100 900;
+    font-style: normal;
+    font-display: swap;
+}
+
+@font-face {
+    font-family: 'JetBrains Mono';
+    src: url('/fonts/JetBrainsMono-Regular.woff2') format('woff2');
+    font-weight: 400;
+    font-style: normal;
+    font-display: swap;
+}
+
+body {
+    background-color: var(--color-bg-base);
+    color: var(--color-text-primary);
+    font-family: var(--font-display);
+}

routes/auth.php

@@ -5,8 +5,9 @@ use Illuminate\Support\Facades\Route;
 use Livewire\Volt\Volt;
 
 Route::middleware('guest')->group(function () {
-    Volt::route('register', 'pages.auth.register')
-        ->name('register');
+    // Registration disabled — Lernschiff is invite-only.
+    // Volt::route('register', 'pages.auth.register')
+    //     ->name('register');
 
     Volt::route('login', 'pages.auth.login')
         ->name('login');

tests/Feature/Auth/RegistrationTest.php

@@ -2,14 +2,12 @@
 
 namespace Tests\Feature\Auth;
 
-use Livewire\Volt\Volt;
+// Lernschiff is invite-only. Self-registration is disabled.
+// Users are created by school-admin or platform-admin via invite.
 
-test('registration screen can be rendered', function () {
-    $response = $this->get('/register');
-
-    $response
-        ->assertOk()
-        ->assertSeeVolt('pages.auth.register');
+test('registration screen is disabled (invite-only)', function () {
+    // /register route is commented out in routes/auth.php — expect 404.
+    $this->get('/register')->assertNotFound();
 });
 
 test('new users can register', function () {

vite.config.js

@@ -1,8 +1,10 @@
 import { defineConfig } from 'vite';
 import laravel from 'laravel-vite-plugin';
+import tailwindcss from '@tailwindcss/vite';
 
 export default defineConfig({
     plugins: [
+        tailwindcss(),
         laravel({
             input: ['resources/css/app.css', 'resources/js/app.js', 'resources/js/auth.js'],
             refresh: true,