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/actions/auth.ts

@@ -4,42 +4,71 @@ import { redirect } from "next/navigation"
 import { headers } from "next/headers"
 import { APIError } from "better-auth/api"
 import { auth } from "@/lib/auth"
+import { verifyTurnstile } from "@/lib/turnstile"
 
 const APP_URL = process.env.NEXT_PUBLIC_APP_URL ?? "http://localhost:3000"
+const CAPTCHA_ERROR = "Please complete the verification challenge and try again."
+
+/** Post-auth destination — only same-site relative paths (blocks open redirects). */
+function safeNext(formData: FormData): string {
+  const next = formData.get("next")
+  if (typeof next === "string" && next.startsWith("/") && !next.startsWith("//") && !next.startsWith("/\\")) {
+    return next
+  }
+  return "/dashboard"
+}
 
 export async function signUp(formData: FormData) {
   const email = formData.get("email") as string
   const password = formData.get("password") as string
   const fullName = formData.get("full_name") as string
+  const captchaToken = formData.get("cf-turnstile-response") as string | null
+
+  const h = await headers()
+  if (!(await verifyTurnstile(captchaToken, h.get("x-forwarded-for")))) {
+    redirect(`/signup?error=${encodeURIComponent(CAPTCHA_ERROR)}`)
+  }
 
   try {
     await auth.api.signUpEmail({
-      body: { email, password, name: fullName },
-      headers: await headers(),
+      // callbackURL is where the verification link lands the user after confirming.
+      body: { email, password, name: fullName, callbackURL: "/dashboard" },
+      headers: h,
     })
   } catch (e) {
     const msg = e instanceof APIError ? e.message : "Sign up failed"
     redirect(`/signup?error=${encodeURIComponent(msg)}`)
   }
 
-  redirect("/dashboard")
+  // When email verification is required, the account isn't usable until confirmed —
+  // send the user to the "check your email" screen instead of the dashboard.
+  if (process.env.REQUIRE_EMAIL_VERIFICATION === "true") {
+    redirect("/signup?success=check-email")
+  }
+  redirect(safeNext(formData))
 }
 
 export async function signIn(formData: FormData) {
   const email = formData.get("email") as string
   const password = formData.get("password") as string
+  const captchaToken = formData.get("cf-turnstile-response") as string | null
+
+  const h = await headers()
+  if (!(await verifyTurnstile(captchaToken, h.get("x-forwarded-for")))) {
+    redirect(`/login?error=${encodeURIComponent(CAPTCHA_ERROR)}`)
+  }
 
   try {
     await auth.api.signInEmail({
       body: { email, password },
-      headers: await headers(),
+      headers: h,
     })
   } catch (e) {
     const msg = e instanceof APIError ? e.message : "Invalid email or password"
     redirect(`/login?error=${encodeURIComponent(msg)}`)
   }
 
-  redirect("/dashboard")
+  redirect(safeNext(formData))
 }
 
 export async function signInWithGoogle() {
@@ -61,11 +90,17 @@ export async function signInWithGoogle() {
 
 export async function resetPassword(formData: FormData) {
   const email = formData.get("email") as string
+  const captchaToken = formData.get("cf-turnstile-response") as string | null
+
+  const h = await headers()
+  if (!(await verifyTurnstile(captchaToken, h.get("x-forwarded-for")))) {
+    redirect(`/forgot-password?error=${encodeURIComponent(CAPTCHA_ERROR)}`)
+  }
 
   try {
     await auth.api.requestPasswordReset({
       body: { email, redirectTo: `${APP_URL}/update-password` },
-      headers: await headers(),
+      headers: h,
     })
   } catch {
     // Always report success so we don't reveal whether an account exists.