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/backend/src/lib/auth.ts

@@ -1,37 +1,34 @@
+import { dash } from '@better-auth/infra';
 import { betterAuth } from 'better-auth';
 import { prismaAdapter } from 'better-auth/adapters/prisma';
 import { openAPI } from 'better-auth/plugins';
 import { db } from './prisma';
-import { dash } from "@better-auth/infra";
 
 export const auth = betterAuth({
-    database: prismaAdapter(db, {
-        provider: 'postgresql',
-    }),
-    secret: process.env.BETTER_AUTH_SECRET,
-    baseURL: process.env.BETTER_AUTH_URL,
-    session: {
-        cookieCache: {
-            enabled: false,
-        },
+  database: prismaAdapter(db, {
+    provider: 'postgresql',
+  }),
+  secret: process.env.BETTER_AUTH_SECRET,
+  baseURL: process.env.BETTER_AUTH_URL,
+  session: {
+    cookieCache: {
+      enabled: false,
     },
-    emailAndPassword: {
-        enabled: true,
+  },
+  emailAndPassword: {
+    enabled: true,
+  },
+  socialProviders: {
+    google: {
+      clientId: process.env.GOOGLE_CLIENT_ID!,
+      clientSecret: process.env.GOOGLE_CLIENT_SECRET!,
     },
-    socialProviders: {
-        google: {
-            clientId: process.env.GOOGLE_CLIENT_ID!,
-            clientSecret: process.env.GOOGLE_CLIENT_SECRET!,
-        },
-    },
-    trustedOrigins: [
-        process.env.APP_BASE_URL ?? 'http://localhost:5173',
-        process.env.BETTER_AUTH_URL ?? 'http://localhost:3000',
-    ],
-    plugins: [
-        openAPI(),
-        dash()
-    ],
+  },
+  trustedOrigins: [
+    process.env.APP_BASE_URL ?? 'http://localhost:5173',
+    process.env.BETTER_AUTH_URL ?? 'http://localhost:3000',
+  ],
+  plugins: [openAPI(), dash()],
 });
 
 export type Session = typeof auth.$Infer.Session.session;

apps/backend/src/lib/avatar.ts

@@ -0,0 +1,17 @@
+import { createHash } from 'node:crypto';
+
+function getGravatarUrl(email: string): string {
+  const hash = createHash('md5').update(email.trim().toLowerCase()).digest('hex');
+  return `https://www.gravatar.com/avatar/${hash}?d=identicon`;
+}
+
+export function resolveAvatarUrl(input: {
+  email: string;
+  image?: string | null;
+}): string {
+  if (input.image) {
+    return input.image;
+  }
+
+  return getGravatarUrl(input.email);
+}