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/activity/route.ts

@@ -3,11 +3,14 @@ import { desc, eq } from "drizzle-orm"
 import { db } from "@/lib/db"
 import { activity_log } from "@/lib/db/schema"
 import { getSessionUser } from "@/lib/session"
+import { getEffectiveOwnerId } from "@/lib/account"
 
 export async function GET(request: Request) {
   const user = await getSessionUser()
   if (!user) return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
 
+  const ownerId = await getEffectiveOwnerId(user.id)
+
   const { searchParams } = new URL(request.url)
   const limit = Math.min(100, parseInt(searchParams.get("limit") ?? "50", 10))
 
@@ -15,7 +18,7 @@ export async function GET(request: Request) {
     const data = await db
       .select()
       .from(activity_log)
-      .where(eq(activity_log.user_id, user.id))
+      .where(eq(activity_log.user_id, ownerId))
       .orderBy(desc(activity_log.created_at))
       .limit(limit)