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>

app/api/stripe/portal/route.ts

@@ -0,0 +1,27 @@
+import { NextResponse } from "next/server"
+import { eq } from "drizzle-orm"
+import { db } from "@/lib/db"
+import { profiles } from "@/lib/db/schema"
+import { getSessionUser } from "@/lib/session"
+import { stripe } from "@/lib/stripe/client"
+
+export async function POST() {
+  const user = await getSessionUser()
+  if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
+
+  const profile = await db.query.profiles.findFirst({
+    where: eq(profiles.id, user.id),
+    columns: { stripe_customer_id: true },
+  })
+
+  if (!profile?.stripe_customer_id) {
+    return NextResponse.json({ error: "No billing account found" }, { status: 400 })
+  }
+
+  const session = await stripe.billingPortal.sessions.create({
+    customer: profile.stripe_customer_id,
+    return_url: `${process.env.NEXT_PUBLIC_APP_URL}/settings/billing`,
+  })
+
+  return NextResponse.json({ url: session.url })
+}