fix(clients): stale signature bug, monthly turnover/annual income fields, senior citizen/PWD classification

- Fix signature-document reads picking the oldest upload instead of the latest across 7 call
  sites (CKYC tab, view/delete-signature dialogs, edit-wizard preview, cashier transaction entry,
  signatory service, record-master) by sorting on document id instead of an unsorted find().
- Add Monthly Turnover and Annual Income fields alongside the renamed Yearly Turnover field.
- Add Senior Citizen (auto-detected from DOB) and Person with Disability classification, with a
  required disability-certificate upload gate before client creation can proceed.
- Add Graduate and Diploma as distinct Education Levels, with diploma-specific degree options.

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

src/app/cashier/transaction-entry/transaction-entry.component.ts

@@ -394,7 +394,12 @@ export class JointHolderDialogComponent implements OnInit {
       this.kyc = kycArr[0] ?? null;
       this.photo = photo ?? null;
       const docs: any[] = Array.isArray(documents) ? documents : [];
-      const sigDoc = docs.find((d: any) => d.name === 'clientSignature' || d.name?.toLowerCase().includes('signature'));
+      // Multiple 'clientSignature' documents can exist for clients who re-cropped/replaced their
+      // signature before uploads became single-slot, so pick the highest id (latest) rather than
+      // the first unordered match.
+      const sigDoc = docs
+        .filter((d: any) => d.name === 'clientSignature' || d.name?.toLowerCase().includes('signature'))
+        .sort((a: any, b: any) => b.id - a.id)[0];
       this.loading = false;
       if (sigDoc) {
         this.http
@@ -1868,7 +1873,12 @@ export class TransactionEntryComponent implements OnInit, OnDestroy {
       this.clientAddresses = Array.isArray(r.addresses) ? r.addresses : [];
       this.clientPhotoUrl = r.photo ?? null;
       const docs: any[] = Array.isArray(r.documents) ? r.documents : [];
-      const sigDoc = docs.find((d: any) => d.name === 'clientSignature' || d.name?.toLowerCase().includes('signature'));
+      // Multiple 'clientSignature' documents can exist for clients who re-cropped/replaced their
+      // signature before uploads became single-slot, so pick the highest id (latest) rather than
+      // the first unordered match.
+      const sigDoc = docs
+        .filter((d: any) => d.name === 'clientSignature' || d.name?.toLowerCase().includes('signature'))
+        .sort((a: any, b: any) => b.id - a.id)[0];
       if (sigDoc) {
         this.http
           .get(`/clients/${clientId}/documents/${sigDoc.id}/attachment`, { responseType: 'blob' })