test(seed-demo): assert demo-inv-001 outcome shares customer ownership

The Copilot Autofix in 3c1c097 weakened the guard test to only check
the demo-outcome-NNN format, which would silently allow a regression
back to demo-outcome-001 (owned by demo-cust-marie) on the
demo-cust-jeanluc invoice.

Strengthen the test to derive the outcome's owning customer from
customerDefs using the deterministic seed mapping
(demo-outcome-NNN -> demo-appt-NNN -> demo-visit-NNN ->
customerDefs[(NNN-1) % len]) and assert it matches the invoice's
customerId. Add an explicit regression guard naming
demo-outcome-001 so the original bug cannot return unnoticed.

Co-authored-by: Richard Knapp <RJK134@users.noreply.github.com>

Author: cursoragent

__tests__/unit/seed.test.ts

@@ -48,14 +48,36 @@ describe('prisma/seed-demo.ts (demo)', () => {
     expect(demoContent).toContain('postcode');
   });
 
-  it('links the first demo invoice to a valid generated customer visit outcome', () => {
+  it('links the first demo invoice to a visit outcome owned by the same customer', () => {
+    // The invoice on line 1322 of seed-demo.ts: demo-inv-001 belongs to
+    // demo-cust-jeanluc and references a visitOutcomeId. The referenced
+    // outcome MUST belong to the same customer or the visit-outcome →
+    // invoice 1:1 link surfaces cross-customer data in the dashboard.
     const invoiceMatch = demoContent.match(
       /id: 'demo-inv-001'[\s\S]*?customerId: 'demo-cust-jeanluc'[\s\S]*?visitOutcomeId: '([^']+)'/
     );
 
     expect(invoiceMatch).not.toBeNull();
+    const outcomeId = invoiceMatch![1];
+    expect(outcomeId).toMatch(/^demo-outcome-\d{3}$/);
+
+    // Resolve the outcome's owning customer using the deterministic seed
+    // logic: demo-outcome-NNN is created for demo-appt-NNN, which uses
+    // demo-visit-NNN, whose customerId = customerDefs[(NNN-1) % len].id.
+    const customerDefIds = Array.from(
+      demoContent.matchAll(/\{ id: '(demo-cust-[a-z]+)',/g),
+      (m) => m[1]
+    );
+    expect(customerDefIds.length).toBeGreaterThanOrEqual(15);
+
+    const outcomeIndex = parseInt(outcomeId.slice('demo-outcome-'.length), 10) - 1;
+    const ownerCustomerId = customerDefIds[outcomeIndex % customerDefIds.length];
+    expect(ownerCustomerId).toBe('demo-cust-jeanluc');
+
+    // Explicit regression guard for the original bug: the invoice
+    // pointed at demo-outcome-001, which is owned by demo-cust-marie.
+    expect(invoiceMatch![0]).not.toContain("visitOutcomeId: 'demo-outcome-001'");
     expect(invoiceMatch![0]).not.toContain("visitOutcomeId: 'demo-outcome-completed'");
-    expect(invoiceMatch![1]).toMatch(/^demo-outcome-\d{3}$/);
   });
 
   it('creates horses linked to customers and yards', () => {