feat(gro-609): add Stripe details to invoice modal and fix stats date filter

- Add GET /api/invoices/:id/stripe-details endpoint to fetch card last4 and
  payment status from Stripe
- Add getPaymentIntentDetails() to payment service
- Fix stats summary query to filter by startOfMonth
- Add cardLast4, paymentStatus, stripeRefundId transient fields to Invoice type
- Display Stripe details (card last4, payment status, refund status) in modal
- Add stripeRefundId and paymentFailureReason to Invoice schema (was missing in dev types)

Ref: GRO-609
Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/routes/invoices.ts

@@ -422,7 +422,7 @@ invoicesRouter.patch(
 
 // ─── Refund ───────────────────────────────────────────────────────────────────
 
-import { processRefund } from "../services/payment.js";
+import { processRefund, getPaymentIntentDetails } from "../services/payment.js";
 
 const refundSchema = z.object({
   amountCents: z.number().int().nonnegative().optional(),
@@ -515,3 +515,30 @@ invoicesRouter.get("/stats/summary", async (c) => {
     methodBreakdown,
   });
 });
+
+// Get Stripe payment details for an invoice (card last4, payment status, refund status)
+invoicesRouter.get("/:id/stripe-details", async (c) => {
+  const db = getDb();
+  const id = c.req.param("id");
+
+  const [invoice] = await db.select().from(invoices).where(eq(invoices.id, id));
+  if (!invoice) return c.json({ error: "Not found" }, 404);
+
+  let cardLast4: string | null = null;
+  let paymentStatus: string | null = null;
+
+  if (invoice.stripePaymentIntentId) {
+    const details = await getPaymentIntentDetails(invoice.stripePaymentIntentId);
+    if (details) {
+      cardLast4 = details.cardLast4;
+      paymentStatus = details.paymentStatus;
+    }
+  }
+
+  return c.json({
+    stripePaymentIntentId: invoice.stripePaymentIntentId,
+    stripeRefundId: invoice.stripeRefundId,
+    cardLast4,
+    paymentStatus,
+  });
+});

apps/api/src/services/payment.ts

@@ -162,3 +162,19 @@ export async function createSetupIntent(customerId: string): Promise<{ clientSec
 
   return { clientSecret: setupIntent.client_secret! };
 }
+
+export async function getPaymentIntentDetails(
+  paymentIntentId: string
+): Promise<{ cardLast4: string | null; paymentStatus: string | null } | null> {
+  const stripe = getStripeClient();
+  if (!stripe) return null;
+
+  const pi = await stripe.paymentIntents.retrieve(paymentIntentId);
+  const cardLast4 = pi.payment_method
+    ? (pi.payment_method as Stripe.PaymentMethod).card?.last4 ?? null
+    : null;
+  return {
+    cardLast4,
+    paymentStatus: pi.status ?? null,
+  };
+}