feat: implementa sistema de logotipo dinâmico

- Adiciona campo 'logo' ao modelo Settings no Prisma
- Atualiza API /api/settings para lidar com upload de logo
- Cria aba Logotipo funcional no admin com upload de imagem
- Atualiza Header para exibir logo dinâmico (fallback para ícone)
- Atualiza Footer para exibir logo dinâmico
- Atualiza Admin Layout para exibir logo dinâmico
- Logo é atualizado em tempo real via evento settings:refresh

frontend/src/app/admin/layout.tsx

@@ -2,6 +2,7 @@
 
 import { useState, useEffect, useRef, useCallback } from 'react';
 import Link from 'next/link';
+import Image from 'next/image';
 import { usePathname, useRouter } from 'next/navigation';
 import { useToast } from '@/contexts/ToastContext';
 import { useConfirm } from '@/contexts/ConfirmContext';
@@ -20,6 +21,7 @@ export default function AdminLayout({
 }) {
   const [isSidebarOpen, setIsSidebarOpen] = useState(true);
   const [user, setUser] = useState<{ name: string; email: string; avatar?: string | null } | null>(null);
+  const [logo, setLogo] = useState<string | null>(null);
   const [isLoading, setIsLoading] = useState(true);
   const [showAvatarModal, setShowAvatarModal] = useState(false);
   const [isUploading, setIsUploading] = useState(false);
@@ -104,6 +106,27 @@ export default function AdminLayout({
       }
     };
     fetchUser();
+
+    // Buscar logo das configurações
+    const fetchLogo = async () => {
+      try {
+        const response = await fetch('/api/settings');
+        if (response.ok) {
+          const data = await response.json();
+          if (data.logo) {
+            setLogo(data.logo);
+          }
+        }
+      } catch (err) {
+        console.error('Erro ao buscar logo:', err);
+      }
+    };
+    fetchLogo();
+
+    // Listener para atualização em tempo real
+    const handleSettingsRefresh = () => fetchLogo();
+    window.addEventListener('settings:refresh', handleSettingsRefresh);
+    return () => window.removeEventListener('settings:refresh', handleSettingsRefresh);
   }, [router]);
 
   useEffect(() => {
@@ -239,7 +262,18 @@ export default function AdminLayout({
       <aside className={`fixed inset-y-0 left-0 z-50 bg-white dark:bg-secondary border-r border-gray-200 dark:border-white/10 transition-all duration-300 ${isSidebarOpen ? 'w-64' : 'w-20'} hidden md:flex flex-col`}>
         <div className="h-20 flex items-center justify-center border-b border-gray-200 dark:border-white/10">
           <Link href="/admin" className="flex items-center gap-3">
-            <i className="ri-building-2-fill text-3xl text-primary"></i>
+            {logo ? (
+              <Image 
+                src={logo} 
+                alt="Logo" 
+                width={32} 
+                height={32} 
+                className="object-contain"
+                unoptimized
+              />
+            ) : (
+              <i className="ri-building-2-fill text-3xl text-primary"></i>
+            )}
             {isSidebarOpen && (
               <div className="flex items-center gap-2 animate-in fade-in duration-300">
                 <span className="text-xl font-bold text-secondary dark:text-white font-headline leading-none">OCCTO</span>