feat: auto-populate patient fields from member ID on eligibility page

When a member ID is typed on the insurance eligibility page, debounced
lookup fills in date of birth, first name, and last name if the patient
already exists in the database.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/Frontend/src/pages/insurance-status-page.tsx

@@ -110,6 +110,33 @@ export default function InsuranceStatusPage() {
     }
   }, [selectedPatient]);
 
+  // Auto-lookup patient by member ID when typed manually
+  useEffect(() => {
+    if (selectedPatient && memberId === (selectedPatient.insuranceId ?? "")) return;
+    if (!memberId) return;
+
+    const timer = setTimeout(async () => {
+      try {
+        const res = await apiRequest("GET", `/api/patients/by-insurance-id?insuranceId=${encodeURIComponent(memberId)}`);
+        if (!res.ok) return;
+        const patient: Patient | null = await res.json();
+        if (patient) {
+          setFirstName(patient.firstName ?? "");
+          setLastName(patient.lastName ?? "");
+          const dob =
+            typeof patient.dateOfBirth === "string"
+              ? parseLocalDate(patient.dateOfBirth)
+              : patient.dateOfBirth ?? null;
+          setDateOfBirth(dob);
+        }
+      } catch {
+        // silently ignore lookup errors
+      }
+    }, 500);
+
+    return () => clearTimeout(timer);
+  }, [memberId, selectedPatient]);
+
   // Add patient mutation
   const addPatientMutation = useMutation({
     mutationFn: async (patient: InsertPatient) => {