fix: match PDF-imported patients by member ID when DOB is missing on record

MassHealth eligibility lookups via the AI chatbot only matched existing
patients on memberId+DOB, so patients imported from PDF extraction (which
have a member ID but no stored birthday) were treated as new/unknown even
though they already exist in the system.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/Backend/src/storage/patients-storage.ts

@@ -11,6 +11,7 @@ export interface IStorage {
   getPatient(id: number): Promise<Patient | undefined>;
   getPatientByInsuranceId(insuranceId: string): Promise<Patient | null>;
   getPatientByInsuranceIdAndDob(insuranceId: string, dob: Date): Promise<Patient | null>;
+  getPatientByInsuranceIdNoDob(insuranceId: string): Promise<Patient | null>;
   getAllPatients(): Promise<Patient[]>;
   getRecentPatients(limit: number, offset: number): Promise<Patient[]>;
   getPatientsByIds(ids: number[]): Promise<Patient[]>;
@@ -74,6 +75,12 @@ export const patientsStorage: IStorage = {
     });
   },
 
+  async getPatientByInsuranceIdNoDob(insuranceId: string): Promise<Patient | null> {
+    return db.patient.findFirst({
+      where: { insuranceId, dateOfBirth: null },
+    });
+  },
+
   async getRecentPatients(limit: number, offset: number): Promise<Patient[]> {
     return db.patient.findMany({
       skip: offset,