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>

scripts/seed-admin.ts

@@ -0,0 +1,64 @@
+/**
+ * Create (or reset) the platform superadmin: admin@demo.test / Admin123!
+ * Sets user.role = 'admin' so both our requireAdmin() gate and the Better Auth
+ * admin plugin authorize it. Password is hashed (Better Auth node scrypt).
+ *
+ * Run: npx tsx scripts/seed-admin.ts
+ */
+import { config } from "dotenv"
+config({ path: ".env.local" })
+process.env.DATABASE_SSL = process.env.DATABASE_SSL ?? "disable"
+
+import { randomUUID } from "node:crypto"
+
+const EMAIL = "admin@demo.test"
+const PASSWORD = "Admin123!"
+
+async function main() {
+  const { db, pool } = await import("../lib/db")
+  const s = await import("../lib/db/schema")
+  const { eq } = await import("drizzle-orm")
+  const { hashPassword } = await import("better-auth/crypto")
+
+  await db.delete(s.user).where(eq(s.user.email, EMAIL))
+
+  const userId = randomUUID()
+  const now = new Date()
+  await db.insert(s.user).values({
+    id: userId,
+    name: "Platform Admin",
+    email: EMAIL,
+    emailVerified: true,
+    role: "admin",
+    createdAt: now,
+    updatedAt: now,
+  })
+  await db.insert(s.account).values({
+    id: randomUUID(),
+    accountId: userId,
+    providerId: "credential",
+    userId,
+    password: await hashPassword(PASSWORD),
+    createdAt: now,
+    updatedAt: now,
+  })
+  await db.insert(s.profiles).values({
+    id: userId,
+    email: EMAIL,
+    full_name: "Platform Admin",
+    plan: "lifetime",
+    onboarding_completed: true,
+  })
+
+  console.log(`✓ Superadmin ready`)
+  console.log(`  email:    ${EMAIL}`)
+  console.log(`  password: ${PASSWORD}`)
+  console.log(`  user id:  ${userId}`)
+  console.log(`  role:     admin`)
+  await pool.end()
+}
+
+main().catch((e) => {
+  console.error("seed-admin failed:", e)
+  process.exit(1)
+})