feat(billing) - facilitate top up in ai chat (#21645)

Today, when a trialing user hits their AI usage cap inside the Ask AI
chat, ending the trial bounces them to the Stripe billing portal (and,
for card-less users, loses their place in the conversation). This PR
makes activating a paid plan / topping up credits feel seamless from
within the chat:

Trial users with a card on file activate their subscription in place,
without leaving the app.
Trial users without a card are sent to the Stripe payment-method portal
and, on return, the trial is ended automatically and they're dropped
back into the exact Ask AI thread they came from.
Credit-exhaustion and trial banners now reflect whether a payment method
exists (Add Credit Card vs Subscribe Now / End Trial Period) and upgrade
inline via a confirmation modal instead of redirecting to Settings.


Uploading Screen Recording 2026-06-16 at 07.51.12.mov…


https://github.com/user-attachments/assets/4ea77273-da63-4b32-b6f1-5ac9e9560651



<!-- This is an auto-generated description by cubic. -->
<a
href="https://cubic.dev/pr/twentyhq/twenty/pull/21645?utm_source=github"
target="_blank" rel="noopener noreferrer"
data-no-image-dialog="true"><picture><source
media="(prefers-color-scheme: dark)"
srcset="https://www.cubic.dev/buttons/review-in-cubic-dark.svg"><source
media="(prefers-color-scheme: light)"
srcset="https://www.cubic.dev/buttons/review-in-cubic-light.svg"><img
alt="Review in cubic"
src="https://www.cubic.dev/buttons/review-in-cubic-dark.svg"></picture></a>
<!-- End of auto-generated description by cubic. -->

packages/twenty-client-sdk/src/metadata/generated/schema.graphql

@@ -964,6 +964,7 @@ type Workspace {
   billingSubscriptions: [BillingSubscription!]!
   installedApplications: [Application!]!
   currentBillingSubscription: BillingSubscription
+  billingCustomer: BillingCustomer
   billingEntitlements: [BillingEntitlement!]!
   hasValidSignedEnterpriseKey: Boolean!
   hasValidEnterpriseValidityToken: Boolean!
@@ -1554,6 +1555,11 @@ type BillingSubscriptionItem {
   billingProduct: BillingProductDTO!
 }
 
+type BillingCustomer {
+  id: UUID!
+  hasPaymentMethod: Boolean
+}
+
 type BillingSubscription {
   id: UUID!
   status: SubscriptionStatus!
@@ -3029,7 +3035,7 @@ type Query {
   apiKey(input: GetApiKeyInput!): ApiKey
   getInviteSuggestions: [InviteSuggestion!]!
   applicationConnectionProviders(applicationId: UUID!): [ApplicationConnectionProvider!]!
-  billingPortalSession(returnUrlPath: String): BillingSession!
+  billingPortalSession(returnUrlPath: String, forPaymentMethodUpdate: Boolean): BillingSession!
   listPlans: [BillingPlan!]!
   getResourceCreditUsage: [BillingResourceCreditUsage!]!
   findWorkspaceInvitations: [WorkspaceInvitation!]!