feat: add superadmin management

components/CourseGrid.tsx

@@ -4,7 +4,6 @@ import { Section, Course } from '../types';
 import { getCourses } from '../services/db';
 import { useAuth } from '../context/AuthContext';
 import { Loader2, ChevronLeft, ChevronRight } from 'lucide-react';
-import { CATEGORIES } from '../constants';
 
 interface CourseGridProps {
   onCourseSelect?: (course: Course) => void;
@@ -100,6 +99,9 @@ export const CourseGrid: React.FC<CourseGridProps> = ({
     }
   };
 
+  const categories = Array.from(new Set<string>(courses.map((course) => course.category)))
+    .sort((left, right) => left.localeCompare(right, 'pt-BR'));
+
   if (loading) {
     return (
       <div className="flex justify-center items-center h-64 w-full">
@@ -108,6 +110,17 @@ export const CourseGrid: React.FC<CourseGridProps> = ({
     );
   }
 
+  if (courses.length === 0) {
+    return (
+      <section className="min-h-[60vh] flex items-center justify-center px-6 pt-28 pb-20">
+        <div className="max-w-md text-center rounded-2xl border border-white/10 bg-zinc-950/80 p-8">
+          <h2 className="text-xl font-bold text-white">Cursos em breve</h2>
+          <p className="mt-3 text-sm leading-relaxed text-gray-400">Ainda não há cursos publicados. Cadastre o primeiro curso no Painel do Instrutor.</p>
+        </div>
+      </section>
+    );
+  }
+
   // Filter courses if a specific category is active
   const filteredCourses = activeCategory === 'all' 
     ? courses 
@@ -178,7 +191,7 @@ export const CourseGrid: React.FC<CourseGridProps> = ({
               Todos os Cursos ({courses.length})
             </button>
 
-            {CATEGORIES.map(cat => {
+            {categories.map(cat => {
               const count = courses.filter(c => c.category === cat).length;
               return (
                 <button