Initial import: property management SaaS + security hardening + admin dashboard

Property Management Network — Next.js 16 (App Router), Better Auth,
Drizzle ORM over PostgreSQL, Stripe, OpenAI, Resend.

Includes:
- Security hardening: access-control/IDOR fixes, TLS-by-default DB layer,
  constant-time cron auth, strict security headers, atomic AI quota gating,
  HTML/email output encoding, demo-backdoor disabled in production.
- Superadmin dashboard at /admin (overview/MRR, server-paginated users with
  ban/impersonate/plan/delete, billing, platform activity + admin audit log,
  AI usage, system health) via the Better Auth admin plugin.
- Seed/migration utility scripts under scripts/.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/ai/client.ts

@@ -0,0 +1,23 @@
+import OpenAI from "openai"
+
+// Lazily construct the OpenAI client so `next build` does NOT require
+// OPENAI_API_KEY — it's only needed at runtime. Call sites keep using
+// `openai.xxx` unchanged; the Proxy builds the real client on first access.
+let _openai: OpenAI | null = null
+
+function getOpenAI(): OpenAI {
+  if (!_openai) {
+    const key = process.env.OPENAI_API_KEY
+    if (!key) throw new Error("OPENAI_API_KEY is not set")
+    _openai = new OpenAI({ apiKey: key })
+  }
+  return _openai
+}
+
+export const openai = new Proxy({} as OpenAI, {
+  get(_target, prop, receiver) {
+    const client = getOpenAI()
+    const value = Reflect.get(client, prop, receiver)
+    return typeof value === "function" ? value.bind(client) : value
+  },
+})