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/(dashboard)/ai/page.tsx

@@ -0,0 +1,41 @@
+import { AiChat } from "./ai-chat"
+import { redirect } from "next/navigation"
+import { and, eq, gte, sql } from "drizzle-orm"
+import { db } from "@/lib/db"
+import { profiles, usage_events } from "@/lib/db/schema"
+import { getSessionUser } from "@/lib/session"
+import { PLAN_LIMITS } from "@/lib/stripe/plans"
+import type { Plan } from "@/types"
+
+export const metadata = { title: "AI Assistant — Property Management Network" }
+
+export default async function AiPage() {
+  const user = await getSessionUser()
+  if (!user) redirect("/login")
+
+  const profile = await db.query.profiles.findFirst({
+    where: eq(profiles.id, user.id),
+    columns: { plan: true },
+  })
+
+  const plan = (profile?.plan ?? "starter") as Plan
+  const limit = PLAN_LIMITS[plan].maxAiCalls
+
+  // Count usage this month
+  const monthStart = new Date()
+  monthStart.setDate(1)
+  monthStart.setHours(0, 0, 0, 0)
+  const [{ count }] = await db
+    .select({ count: sql<number>`count(*)::int` })
+    .from(usage_events)
+    .where(
+      and(
+        eq(usage_events.user_id, user.id),
+        gte(usage_events.created_at, monthStart.toISOString())
+      )
+    )
+
+  const used = count ?? 0
+
+  return <AiChat plan={plan} limit={limit} used={used} />
+}