Consolidate audit-fixes branch: webhooks, integrations, and deploy hardening

Batch commit of the pending working tree on security/audit-fixes-2026-07.
Major areas:
- Outbound webhooks / Zapier: schema + signed delivery with retries, public
  v1 API (REST-hook subscribe/unsubscribe), settings UI, cron drain.
- Deploy hardening: email via SMTP2GO (Resend fully removed), verified DB TLS
  (DATABASE_SSL=require + DATABASE_CA), storage fails loud in production when
  Spaces is unconfigured instead of silently using ephemeral disk.
- Integrations & features (concurrent work): accounting (QuickBooks/Xero),
  e-signature (DocuSign/Dropbox Sign), PayPal, geocoding/maps, onboarding,
  expanded legal pages.
- DB migrations 0006–0009.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/api/export/tenants/route.ts

@@ -4,13 +4,16 @@ import { db } from "@/lib/db"
 import { tenants } from "@/lib/db/schema"
 import { getSessionUser } from "@/lib/session"
 import { toCsv } from "@/lib/db/admin-queries"
+import { getEffectiveOwnerId } from "@/lib/account"
 
 export async function GET() {
   const user = await getSessionUser()
   if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
 
+  const ownerId = await getEffectiveOwnerId(user.id)
+
   const rows = await db.query.tenants.findMany({
-    where: eq(tenants.user_id, user.id),
+    where: eq(tenants.user_id, ownerId),
     with: {
       property: { columns: { name: true } },
       unit: { columns: { unit_number: true } },