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>

lib/db/index.ts

@@ -3,9 +3,9 @@ import { Pool, types } from "pg"
 import * as schema from "./schema"
 
 // ── pg type parsers ───────────────────────────────────────────────
-// Make the driver return the same value shapes the app relied on under
-// Supabase/PostgREST, so the ~hundreds of existing read sites keep working:
-//   numeric  -> JS number (was parsed as number by PostgREST)
+// Make the driver return the value shapes the app relies on across its
+// ~hundreds of read sites:
+//   numeric  -> JS number
 //   date     -> "YYYY-MM-DD" string
 //   timestamp / timestamptz -> ISO 8601 string
 types.setTypeParser(1700, (v) => (v === null ? null : parseFloat(v))) // numeric