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/team.ts

@@ -0,0 +1,84 @@
+"use server"
+
+import { and, eq, ne } from "drizzle-orm"
+import { db } from "@/lib/db"
+import { account_members } from "@/lib/db/schema"
+import { getSessionUser } from "@/lib/session"
+
+export type AcceptInviteResult =
+  | { ok: true }
+  | { ok: false; error: string }
+
+/**
+ * Accept a team invite by token.
+ *
+ * Requires an authenticated session (the page redirects to /login first).
+ * On success sets member_id = current user, status='active', accepted_at=now.
+ * A user can be an active member of at most one account, so we block if the
+ * caller is already active somewhere else. Handles invalid / already-used /
+ * revoked tokens gracefully.
+ */
+export async function acceptInvite(token: string): Promise<AcceptInviteResult> {
+  const user = await getSessionUser()
+  if (!user) return { ok: false, error: "You must be signed in to accept an invite." }
+
+  const invite = await db.query.account_members.findFirst({
+    where: eq(account_members.invite_token, token),
+  })
+
+  if (!invite) {
+    return { ok: false, error: "This invite link is invalid or has expired." }
+  }
+
+  if (invite.status === "revoked") {
+    return { ok: false, error: "This invite has been revoked by the account owner." }
+  }
+
+  // Already accepted — by this user (fine, treat as success) or someone else.
+  if (invite.status === "active") {
+    if (invite.member_id === user.id) return { ok: true }
+    return { ok: false, error: "This invite has already been accepted." }
+  }
+
+  // Can't be a member of your own account.
+  if (invite.owner_id === user.id) {
+    return { ok: false, error: "You can't accept an invite to your own account." }
+  }
+
+  // A user may be an active member of at most one account.
+  const existingMembership = await db.query.account_members.findFirst({
+    where: and(
+      eq(account_members.member_id, user.id),
+      eq(account_members.status, "active"),
+      ne(account_members.id, invite.id)
+    ),
+  })
+  if (existingMembership) {
+    return {
+      ok: false,
+      error:
+        "You're already an active member of another account. Leave it before joining a new one.",
+    }
+  }
+
+  try {
+    // Guard the update on status='pending' so two concurrent accepts can't both win.
+    const [updated] = await db
+      .update(account_members)
+      .set({
+        member_id: user.id,
+        status: "active",
+        accepted_at: new Date().toISOString(),
+      })
+      .where(and(eq(account_members.id, invite.id), eq(account_members.status, "pending")))
+      .returning({ id: account_members.id })
+
+    if (!updated) {
+      return { ok: false, error: "This invite is no longer available." }
+    }
+  } catch {
+    return { ok: false, error: "Something went wrong accepting the invite. Please try again." }
+  }
+
+  return { ok: true }
+}