fix: centralizar OnboardingModal em /organizations e evitar reabertura (#15)

O modal de onboarding era disparado tanto na LoginPage quanto no AppShell
com navegação conflitante, fazendo ele fechar e reabrir ao escolher uma
opção. Agora o login sem org redireciona para /organizations, o AppShell
redireciona usuários sem org para lá, e o modal é exibido uma única vez
pela OrganizationsPage.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/components/AppShell.tsx

@@ -1,4 +1,4 @@
-import React, { useState } from "react";
+import { useState } from "react";
 import {
   Layout,
   ListTodo,
@@ -18,9 +18,8 @@ import {
   Users,
   PlusCircle,
 } from "lucide-react";
-import { NavLink, Outlet, Navigate, Link } from "react-router-dom";
+import { NavLink, Outlet, Navigate, Link, useLocation } from "react-router-dom";
 import { useAuth } from "../contexts/AuthContext";
-import { OnboardingModal } from "./OnboardingModal";
 
 import { cn } from "../lib/utils";
 import { motion } from "framer-motion";
@@ -44,7 +43,7 @@ const dropdownItemClassName = ({ isActive }: { isActive: boolean }) =>
 export function AppShell() {
   const { user, isAuthenticated, isLoading, logout, activeOrg, setActiveOrg } =
     useAuth();
-  const [showOrgModal, setShowOrgModal] = useState(false);
+  const location = useLocation();
   const [showOrgSwitcher, setShowOrgSwitcher] = useState(false);
   const [showTasksDropdown, setShowTasksDropdown] = useState(false);
   const [showTeamDropdown, setShowTeamDropdown] = useState(false);
@@ -53,12 +52,6 @@ export function AppShell() {
   const isAdmin =
     activeOrg?.roles.includes("OWNER") || activeOrg?.roles.includes("ADMIN");
 
-  React.useEffect(() => {
-    if (isAuthenticated && user && user.organizations.length === 0) {
-      setShowOrgModal(true);
-    }
-  }, [isAuthenticated, user]);
-
   if (isLoading) {
     return (
       <div className="flex min-h-screen items-center justify-center bg-app-bg text-brand">
@@ -71,6 +64,15 @@ export function AppShell() {
     return <Navigate to="/login" replace />;
   }
 
+  if (
+    isAuthenticated &&
+    user &&
+    user.organizations.length === 0 &&
+    location.pathname !== "/organizations"
+  ) {
+    return <Navigate to="/organizations" replace />;
+  }
+
   return (
     <div className="flex min-h-screen flex-col bg-app-bg font-sans text-text-main">
       {/* Top Navigation */}
@@ -622,10 +624,6 @@ export function AppShell() {
           </div>
         </nav>
       </footer>
-      <OnboardingModal
-        isOpen={showOrgModal}
-        onClose={() => setShowOrgModal(false)}
-      />
     </div>
   );
 }

frontend/src/pages/LoginPage.tsx

@@ -3,13 +3,11 @@ import { useNavigate, Link } from 'react-router-dom'
 import { motion } from 'framer-motion'
 import { Mail, Lock, LogIn, Layout } from 'lucide-react'
 import { useAuth } from '../contexts/AuthContext'
-import { OnboardingModal } from '../components/OnboardingModal'
 
 export const LoginPage: React.FC = () => {
   const [email, setEmail] = useState('')
   const [password, setPassword] = useState('')
   const [isLoading, setIsLoading] = useState(false)
-  const [showOnboarding, setShowOnboarding] = useState(false)
   const navigate = useNavigate()
   const { login } = useAuth()
 
@@ -20,7 +18,7 @@ export const LoginPage: React.FC = () => {
     try {
       const response = await login(email, password)
       if (response.organizations.length === 0) {
-        setShowOnboarding(true)
+        navigate('/organizations')
       } else {
         navigate('/')
       }
@@ -113,13 +111,6 @@ export const LoginPage: React.FC = () => {
           </div>
         </div>
       </motion.div>
-      <OnboardingModal 
-        isOpen={showOnboarding} 
-        onClose={() => {
-          setShowOnboarding(false)
-          navigate('/')
-        }} 
-      />
     </div>
   )
 }

frontend/src/pages/OrganizationsPage.tsx

@@ -19,9 +19,13 @@ import { Link } from 'react-router-dom'
 import { useAuth } from '../contexts/AuthContext'
 import { cn } from '../lib/utils'
 import { organizationService } from '../services/organizationService'
+import { OnboardingModal } from '../components/OnboardingModal'
 
 export function OrganizationsPage() {
   const { user, activeOrg, setActiveOrg, refreshUser } = useAuth()
+  const [showOnboarding, setShowOnboarding] = useState(
+    () => (user?.organizations.length ?? 0) === 0,
+  )
   const [showCreateModal, setShowCreateModal] = useState(false)
   const [newOrgName, setNewOrgName] = useState('')
   const [isCreating, setIsCreating] = useState(false)
@@ -250,6 +254,11 @@ export function OrganizationsPage() {
         </div>
       </div>
 
+      <OnboardingModal
+        isOpen={showOnboarding}
+        onClose={() => setShowOnboarding(false)}
+      />
+
       {/* Create Organization Modal */}
       <AnimatePresence>
         {showCreateModal && (