feat: add complex user invitation and management features

- Implemented complex member and invitation schemas using Zod for validation.
- Created new API endpoints for inviting, accepting, revoking, and canceling complex user invitations.
- Developed handlers for managing complex users, including listing, inviting, revoking, and canceling invitations.
- Added frontend components for displaying and managing complex users and invitations.
- Introduced session storage management for pending invitations.
- Integrated Gravatar for user avatars based on email.
- Created database migration for complex invitations table.

apps/frontend/src/features/login/login-page.tsx

@@ -3,6 +3,7 @@ import { Field, FieldError, FieldLabel } from '@/components/ui/field';
 import { Input } from '@/components/ui/input';
 import { apiClient, authClient } from '@/lib/api-client';
 import { useAuth } from '@/lib/auth';
+import { acceptStoredPendingInvite } from '@/lib/invitations';
 import { zodResolver } from '@hookform/resolvers/zod';
 import { Link, useNavigate } from '@tanstack/react-router';
 import { useState } from 'react';
@@ -39,6 +40,7 @@ export function LoginPage({ redirectTo = '/' }: LoginPageProps) {
   });
 
   async function handlePostLogin() {
+    await acceptStoredPendingInvite(apiClient.complexes.acceptPendingInvitations);
     const complexes = await apiClient.complexes.listMine();
 
     if (complexes.length === 0) {