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>

components/forms/checkout-button.tsx

@@ -0,0 +1,35 @@
+"use client"
+
+import { useState } from "react"
+import { cn } from "@/lib/utils"
+
+export function CheckoutButton({ plan, label, highlight }: { plan: string; label: string; highlight?: boolean }) {
+  const [loading, setLoading] = useState(false)
+
+  async function handleClick() {
+    setLoading(true)
+    const res = await fetch("/api/stripe/checkout", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({ plan }),
+    })
+    const data = await res.json()
+    if (data.url) window.location.href = data.url
+    else setLoading(false)
+  }
+
+  return (
+    <button
+      onClick={handleClick}
+      disabled={loading}
+      className={cn(
+        "w-full rounded-lg py-2 text-xs font-semibold transition disabled:opacity-50",
+        highlight
+          ? "bg-indigo-600 text-white hover:bg-indigo-500"
+          : "border border-white/10 text-white/70 hover:border-white/20 hover:text-white"
+      )}
+    >
+      {loading ? "Loading..." : label}
+    </button>
+  )
+}