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/ui/back-button.tsx

@@ -0,0 +1,28 @@
+"use client"
+
+import { useRouter } from "next/navigation"
+import { ArrowLeft } from "lucide-react"
+
+interface BackButtonProps {
+  href?: string
+  label?: string
+}
+
+export function BackButton({ href, label = "Back" }: BackButtonProps) {
+  const router = useRouter()
+
+  function handleClick() {
+    if (href) router.push(href)
+    else router.back()
+  }
+
+  return (
+    <button
+      onClick={handleClick}
+      className="mb-4 flex items-center gap-1.5 text-sm text-white/40 transition hover:text-white/80"
+    >
+      <ArrowLeft className="h-4 w-4" />
+      {label}
+    </button>
+  )
+}