feat: add authentication, user management, and admin features

Added comprehensive authentication and authorization system:

Authentication System:
- Better Auth integration with session management
- Login/logout pages and API routes
- Middleware for route protection
- Auth utilities and client libraries

User Management:
- User list, detail, and invite pages
- User API endpoints (CRUD operations)
- Session management for users
- Profile settings page

Role-Based Access Control:
- Role management pages (list, create, edit)
- Permission system with granular controls
- Role assignment to users
- Role API endpoints

Admin Features:
- Audit log page for tracking system events
- Admin settings page
- Audit service for logging user actions

Additional Features:
- Quotes management pages and components
- SalesBldr API integration
- Email service for notifications

Configuration & Documentation:
- Updated docker-compose.yml
- MCP server configuration (mcp.json)
- CVE-2025-55182 security review documentation
- Standards guide and PRD documents
- Re-enabling authentication documentation

Database Migrations:
- 012: Auth tables (users, sessions, accounts, verifications)
- 013: Role tables (roles, permissions, role_permissions, user_roles)
- 014: Admin settings table

UI Updates:
- Updated dashboard layout
- Enhanced app layout with auth integration

app/api/admin/users/invite/route.ts

@@ -0,0 +1,72 @@
+import { NextRequest, NextResponse } from "next/server";
+import { Pool } from "pg";
+import { requireAdmin, getSession } from "@/lib/auth-utils";
+import { sendInvitationEmail } from "@/lib/services/email";
+
+const pool = new Pool({
+  connectionString: process.env.DATABASE_URL,
+});
+
+// POST /api/admin/users/invite - Send invitation email
+export async function POST(request: NextRequest) {
+  const { session, error } = await requireAdmin();
+  if (error) return error;
+
+  try {
+    const body = await request.json();
+    const { email, name, role = "user" } = body;
+
+    if (!email) {
+      return NextResponse.json(
+        { error: "Email is required" },
+        { status: 400 }
+      );
+    }
+
+    // Check if user already exists
+    const existingUser = await pool.query(
+      'SELECT id FROM "user" WHERE email = $1',
+      [email]
+    );
+
+    if (existingUser.rows.length > 0) {
+      return NextResponse.json(
+        { error: "User with this email already exists" },
+        { status: 409 }
+      );
+    }
+
+    // Create the user with requires_setup flag
+    const id = crypto.randomUUID();
+    await pool.query(
+      `INSERT INTO "user" (id, name, email, role, email_verified, requires_setup, created_at, updated_at)
+       VALUES ($1, $2, $3, $4, false, true, NOW(), NOW())`,
+      [id, name || email.split("@")[0], email, role]
+    );
+
+    // Generate invitation URL (magic link)
+    const baseUrl = process.env.BETTER_AUTH_URL || "http://localhost:3000";
+    const inviteUrl = `${baseUrl}/auth/sign-in?email=${encodeURIComponent(email)}`;
+
+    // Get inviter name
+    const inviterName = session?.user.name || "An administrator";
+
+    // Send invitation email
+    await sendInvitationEmail({
+      email,
+      inviterName,
+      url: inviteUrl,
+    });
+
+    return NextResponse.json({
+      success: true,
+      message: "Invitation sent successfully",
+    });
+  } catch (error) {
+    console.error("Error sending invitation:", error);
+    return NextResponse.json(
+      { error: "Failed to send invitation" },
+      { status: 500 }
+    );
+  }
+}