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/documents/route.ts

@@ -0,0 +1,85 @@
+import { NextResponse } from "next/server"
+import { and, desc, eq } from "drizzle-orm"
+import { db } from "@/lib/db"
+import { documents, properties } from "@/lib/db/schema"
+import { getSessionUser } from "@/lib/session"
+import { saveFile } from "@/lib/storage"
+
+export async function GET(request: Request) {
+  const user = await getSessionUser()
+  if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
+
+  const { searchParams } = new URL(request.url)
+  const propertyId = searchParams.get("property_id")
+
+  let propertyName = ""
+  if (propertyId) {
+    const prop = await db.query.properties.findFirst({
+      where: and(eq(properties.id, propertyId), eq(properties.user_id, user.id)),
+      columns: { name: true },
+    })
+    propertyName = prop?.name ?? ""
+  }
+
+  const data = await db.query.documents.findMany({
+    where: and(
+      eq(documents.user_id, user.id),
+      propertyId ? eq(documents.property_id, propertyId) : undefined
+    ),
+    orderBy: desc(documents.created_at),
+  })
+
+  return NextResponse.json({ documents: data, propertyName })
+}
+
+export async function POST(request: Request) {
+  const user = await getSessionUser()
+  if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
+
+  const contentType = request.headers.get("content-type") ?? ""
+
+  if (contentType.includes("multipart/form-data")) {
+    const fd = await request.formData()
+    const file = fd.get("file") as File | null
+    const propertyId = fd.get("property_id") as string
+    const name = fd.get("name") as string
+    const category = ((fd.get("category") as string) || "other") as typeof documents.$inferInsert.category
+
+    if (!file) return NextResponse.json({ error: "No file provided" }, { status: 400 })
+    if (file.size > 20 * 1024 * 1024) return NextResponse.json({ error: "File too large (max 20 MB)" }, { status: 400 })
+
+    // Verify the property belongs to the user before attaching a document to it.
+    const prop = await db.query.properties.findFirst({
+      where: and(eq(properties.id, propertyId), eq(properties.user_id, user.id)),
+      columns: { id: true },
+    })
+    if (!prop) return NextResponse.json({ error: "Property not found" }, { status: 404 })
+
+    const { key, size, type } = await saveFile(file, { userId: user.id, scope: "documents" })
+
+    const [data] = await db
+      .insert(documents)
+      .values({
+        user_id: user.id,
+        property_id: propertyId,
+        name: name || file.name,
+        category,
+        file_url: `/api/files/${key}`,
+        storage_path: key,
+        file_type: type,
+        file_size: size,
+      })
+      .returning()
+
+    return NextResponse.json(data, { status: 201 })
+  }
+
+  // JSON fallback (metadata only)
+  const body = (await request.json()) as Record<string, unknown>
+  const [data] = await db
+    .insert(documents)
+    .values({ ...(body as typeof documents.$inferInsert), user_id: user.id })
+    .returning()
+
+  return NextResponse.json(data, { status: 201 })
+}