feat: integra autenticação do front com API real

- useAuth.ts: substitui mock por $fetch no /auth/login e /auth/logout
- login.vue: adiciona campo "Organização" (slug) no formulário
- nuxt.config.ts: adiciona runtimeConfig.public.apiBase

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

front-end/app/composables/useAuth.ts

@@ -1,6 +1,3 @@
-const MOCK_EMAIL = 'admin@licitatche.gov.br'
-const MOCK_PASSWORD = 'admin123'
-
 interface AuthUser {
   nome: string
   email: string
@@ -8,26 +5,54 @@ interface AuthUser {
 }
 
 export function useAuth() {
+  const { public: { apiBase } } = useRuntimeConfig()
+
   const user = useState<AuthUser | null>('auth_user', () => null)
-  const token = useCookie('auth_token', { maxAge: 60 * 60 * 8 })
+  const token = useCookie<string | null>('auth_token', { maxAge: 60 * 60 * 8 })
+  const refreshToken = useCookie<string | null>('refresh_token', { maxAge: 60 * 60 * 24 * 7 })
 
   const isAuthenticated = computed(() => !!token.value)
 
+  // Restaura usuário do token ao recarregar
   if (token.value && !user.value) {
-    user.value = { nome: 'Admin', email: MOCK_EMAIL, papel: 'Administrador' }
+    try {
+      const payload = JSON.parse(atob(token.value.split('.')[1]))
+      user.value = { nome: payload.email.split('@')[0], email: payload.email, papel: payload.role }
+    } catch {
+      token.value = null
+    }
   }
 
-  async function login(email: string, password: string): Promise<{ success: boolean; error?: string }> {
-    if (email === MOCK_EMAIL && password === MOCK_PASSWORD) {
-      token.value = 'mock_token_' + Date.now()
-      user.value = { nome: 'Admin', email, papel: 'Administrador' }
+  async function login(email: string, password: string, slug: string): Promise<{ success: boolean; error?: string }> {
+    try {
+      const res = await $fetch<{ access_token: string; refresh_token: string }>(`${apiBase}/auth/login`, {
+        method: 'POST',
+        body: { email, password, slug },
+      })
+
+      token.value = res.access_token
+      refreshToken.value = res.refresh_token
+
+      const payload = JSON.parse(atob(res.access_token.split('.')[1]))
+      user.value = { nome: payload.email.split('@')[0], email: payload.email, papel: payload.role }
+
       return { success: true }
+    } catch (err: any) {
+      const msg = err?.data?.error || 'E-mail, senha ou organização incorretos.'
+      return { success: false, error: msg }
     }
-    return { success: false, error: 'E-mail ou senha incorretos.' }
   }
 
   function logout() {
+    // Fire-and-forget logout no back (invalida refresh token)
+    if (refreshToken.value) {
+      $fetch(`${apiBase}/auth/logout`, {
+        method: 'POST',
+        body: { refresh_token: refreshToken.value },
+      }).catch(() => {})
+    }
     token.value = null
+    refreshToken.value = null
     user.value = null
     navigateTo('/login')
   }