Security hardening from 2026-07-01 audit

- Exclude supabase/ from Docker build context (leaked service_role key file)
- /api/files: exact per-user namespace match + reject path traversal;
  storage resolveKey rejects ".."/"." segments (fixes cross-user file read)
- Add ownsProperty/Unit/Tenant checks to tenants, maintenance (landlord path),
  and documents (JSON branch, now field-whitelisted) create handlers
- Escape user data in follow-up + payment-link emails (reuse escapeHtml)
- Neutralize CSV formula injection in toCsv + export routes
- Tighter sign-in rate limit (10/min); env-gated email verification + sender
- Per-request nonce CSP; drop script-src 'unsafe-inline' (styles unchanged)
- Add input length bounds; validate follow-ups POST body

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/api/expenses/export/route.ts

@@ -3,6 +3,7 @@ import { and, desc, eq } from "drizzle-orm"
 import { db } from "@/lib/db"
 import { expenses } from "@/lib/db/schema"
 import { getSessionUser } from "@/lib/session"
+import { toCsv } from "@/lib/db/admin-queries"
 
 export async function GET(request: Request) {
   const user = await getSessionUser()
@@ -22,9 +23,9 @@ export async function GET(request: Request) {
     orderBy: desc(expenses.expense_date),
   })
 
-  const rows = [
+  const csv = toCsv(
     ["Date", "Description", "Category", "Amount", "Property", "Vendor", "Recurring", "Recurrence", "Notes"],
-    ...data.map((e) => [
+    data.map((e) => [
       e.expense_date,
       e.description,
       e.category,
@@ -34,10 +35,8 @@ export async function GET(request: Request) {
       e.is_recurring ? "Yes" : "No",
       e.recurrence ?? "",
       e.notes ?? "",
-    ]),
-  ]
-
-  const csv = rows.map((r) => r.map((v) => `"${String(v).replace(/"/g, '""')}"`).join(",")).join("\n")
+    ])
+  )
 
   return new Response(csv, {
     headers: {