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/cron/follow-ups/route.ts

@@ -0,0 +1,35 @@
+import { NextResponse } from "next/server"
+import { eq } from "drizzle-orm"
+import { db } from "@/lib/db"
+import { follow_up_rules } from "@/lib/db/schema"
+import { isAuthorizedCron } from "@/lib/cron-auth"
+import { runFollowUpsForUser } from "@/lib/follow-ups"
+
+// Automated follow-ups cron: runs every user's active follow-up rules.
+// Runs daily at 10:00 UTC (see functions/project.yml → follow-ups trigger).
+export async function GET(request: Request) {
+  if (!isAuthorizedCron(request)) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 })
+  }
+
+  // Distinct user ids that have at least one active follow-up rule.
+  const rows = await db
+    .selectDistinct({ user_id: follow_up_rules.user_id })
+    .from(follow_up_rules)
+    .where(eq(follow_up_rules.is_active, true))
+
+  let processed = 0
+  let total = 0
+
+  for (const { user_id } of rows) {
+    try {
+      const result = await runFollowUpsForUser(user_id)
+      total += result.sent
+      processed++
+    } catch (err) {
+      console.error(`follow-ups cron failed for user ${user_id}:`, err)
+    }
+  }
+
+  return NextResponse.json({ processed, sent: total })
+}