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/(dashboard)/properties/[propertyId]/units/new/page.tsx

@@ -3,6 +3,7 @@ import { and, eq } from "drizzle-orm"
 import { db } from "@/lib/db"
 import { properties } from "@/lib/db/schema"
 import { getSessionUser } from "@/lib/session"
+import { getEffectiveOwnerId } from "@/lib/account"
 import { BackButton } from "@/components/ui/back-button"
 import { UnitForm } from "@/components/forms/unit-form"
 
@@ -12,10 +13,12 @@ export default async function NewUnitPage({ params }: { params: Promise<{ proper
   const user = await getSessionUser()
   if (!user) redirect("/login")
 
+  const ownerId = await getEffectiveOwnerId(user.id)
+
   const { propertyId } = await params
 
   const property = await db.query.properties.findFirst({
-    where: and(eq(properties.id, propertyId), eq(properties.user_id, user.id)),
+    where: and(eq(properties.id, propertyId), eq(properties.user_id, ownerId)),
     columns: { id: true, name: true },
   })