fix(clients): minor-age threshold to 18, senior/PWD doc reload, in-app document preview dialog

- Raise isMinor threshold from age <10 to <18 (legal definition), cascading correctly to
  guardian requirement, KYC document filtering, and Education Level/Degree Qualification
  visibility (now shown for all ages, not hidden for minors).
- Load and display previously-uploaded Senior Citizen proof / PWD certificate documents on
  edit (view/replace/remove), instead of always showing an empty upload prompt.
- Fix seniorPwdDocsComplete to accept an existing certificate, not just a freshly-picked file.
- Add DocumentPreviewDialogComponent: a reusable in-app modal (image/PDF/download) used in
  place of window.open() for saved KYC/address/senior-citizen/PWD documents — avoids popup
  blockers (fired only after the async download resolved) and Chrome/Edge's failure to paint
  large base64 data: URLs on first open.

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

src/app/clients/client-stepper/client-general-step/client-general-step.component.ts

@@ -46,6 +46,7 @@ import { MatSelectTrigger } from '@angular/material/select';
 import { MatTooltip } from '@angular/material/tooltip';
 import { MatDialog, MAT_DIALOG_DATA, MatDialogContent, MatDialogClose } from '@angular/material/dialog';
 import { STANDALONE_SHARED_IMPORTS } from 'app/standalone-shared.module';
+import { DocumentPreviewDialogComponent } from '../../shared/document-preview-dialog/document-preview-dialog.component';
 import { DateFormatPipe } from '../../../pipes/date-format.pipe';
 import { SanctionsVerifyDialogComponent } from './sanctions-verify-dialog.component';
 import { DipVerifyDialogComponent } from './dip-verify-dialog.component';
@@ -98,6 +99,11 @@ export class ClientGeneralStepComponent implements OnInit, OnDestroy, OnChanges
   seniorCitizenProofFile: File | null = null;
   pwdCertificateFile: File | null = null;
 
+  /** Previously-uploaded documents, loaded in edit mode so the certificate doesn't appear to
+   * "disappear" on reopening — the raw File properties above only ever hold a fresh selection. */
+  existingSeniorCitizenProofDoc: { id: string; name: string } | null = null;
+  existingPwdCertificateDoc: { id: string; name: string } | null = null;
+
   /** Disability categories (per the Rights of Persons with Disabilities Act, 2016) — fetched from
    * m_code_value (code "PwdCategory") via the client template, same as occupationCategoryOptions.
    * Admins can add/reorder/deactivate entries from System -> Manage Codes without a code change. */
@@ -111,7 +117,8 @@ export class ClientGeneralStepComponent implements OnInit, OnDestroy, OnChanges
   get seniorPwdDocsComplete(): boolean {
     const pwdOk =
       !this.createClientForm.get('isPwd')?.value ||
-      (!!this.pwdCertificateFile && !!this.createClientForm.get('pwdCategoryId')?.value);
+      ((!!this.pwdCertificateFile || !!this.existingPwdCertificateDoc) &&
+        !!this.createClientForm.get('pwdCategoryId')?.value);
     return pwdOk;
   }
 
@@ -141,6 +148,93 @@ export class ClientGeneralStepComponent implements OnInit, OnDestroy, OnChanges
     this.pwdCertificateFile = null;
   }
 
+  /** Loads previously-uploaded senior-citizen-proof / PWD-certificate documents in edit mode —
+   * mirrors the KYC step's loadExistingSignature() pattern so re-opening edit shows what's
+   * already on file instead of an empty upload prompt. */
+  private loadExistingSeniorPwdDocuments(): void {
+    const clientId = this.clientData?.id;
+    if (!clientId) {
+      return;
+    }
+    this.clientService.getClientDocuments(clientId.toString()).subscribe({
+      next: (documents: any[]) => {
+        const seniorDoc = documents
+          ?.filter((d: any) => d.name === 'seniorCitizenProof')
+          ?.sort((a: any, b: any) => b.id - a.id)?.[0];
+        if (seniorDoc?.id) {
+          this.existingSeniorCitizenProofDoc = {
+            id: seniorDoc.id.toString(),
+            name: seniorDoc.fileName || 'Senior Citizen Proof'
+          };
+        }
+        const pwdDoc = documents
+          ?.filter((d: any) => d.name === 'pwdCertificate')
+          ?.sort((a: any, b: any) => b.id - a.id)?.[0];
+        if (pwdDoc?.id) {
+          this.existingPwdCertificateDoc = {
+            id: pwdDoc.id.toString(),
+            name: pwdDoc.fileName || 'Disability Certificate'
+          };
+        }
+      },
+      error: () => {}
+    });
+  }
+
+  viewExistingSeniorCitizenProof(): void {
+    const clientId = this.clientData?.id;
+    if (!clientId || !this.existingSeniorCitizenProofDoc) {
+      return;
+    }
+    this.clientService.downloadClientDocument(clientId.toString(), this.existingSeniorCitizenProofDoc.id).subscribe({
+      next: (blob: any) =>
+        this.dialog.open(DocumentPreviewDialogComponent, {
+          data: {
+            blob,
+            title: this.existingSeniorCitizenProofDoc?.name,
+            fileName: this.existingSeniorCitizenProofDoc?.name
+          }
+        }),
+      error: () => {}
+    });
+  }
+
+  removeExistingSeniorCitizenProof(): void {
+    const clientId = this.clientData?.id;
+    if (!clientId || !this.existingSeniorCitizenProofDoc) {
+      return;
+    }
+    this.clientService.deleteClientDocument(clientId.toString(), this.existingSeniorCitizenProofDoc.id).subscribe({
+      next: () => (this.existingSeniorCitizenProofDoc = null),
+      error: () => {}
+    });
+  }
+
+  viewExistingPwdCertificate(): void {
+    const clientId = this.clientData?.id;
+    if (!clientId || !this.existingPwdCertificateDoc) {
+      return;
+    }
+    this.clientService.downloadClientDocument(clientId.toString(), this.existingPwdCertificateDoc.id).subscribe({
+      next: (blob: any) =>
+        this.dialog.open(DocumentPreviewDialogComponent, {
+          data: { blob, title: this.existingPwdCertificateDoc?.name, fileName: this.existingPwdCertificateDoc?.name }
+        }),
+      error: () => {}
+    });
+  }
+
+  removeExistingPwdCertificate(): void {
+    const clientId = this.clientData?.id;
+    if (!clientId || !this.existingPwdCertificateDoc) {
+      return;
+    }
+    this.clientService.deleteClientDocument(clientId.toString(), this.existingPwdCertificateDoc.id).subscribe({
+      next: () => (this.existingPwdCertificateDoc = null),
+      error: () => {}
+    });
+  }
+
   /** Minimum date allowed. */
   minDate = new Date(2000, 0, 1);
   /** Maximum date allowed. */
@@ -203,7 +297,7 @@ export class ClientGeneralStepComponent implements OnInit, OnDestroy, OnChanges
   ];
   /** Calculated age detail string (Y/M/D) */
   calculatedAgeDetail: string | null = null;
-  /** Whether client is a minor (age < 10) */
+  /** Whether client is a minor (age < 18) */
   isMinor = false;
   /** Whether client is a senior citizen (age >= 60) — auto-detected from Date of Birth */
   isSeniorCitizen = false;
@@ -600,6 +694,7 @@ export class ClientGeneralStepComponent implements OnInit, OnDestroy, OnChanges
    */
   private prefillForEdit() {
     const data = this.clientData;
+    this.loadExistingSeniorPwdDocuments();
 
     // Patch all base controls that exist on the form
     this.createClientForm.patchValue({
@@ -980,7 +1075,7 @@ export class ClientGeneralStepComponent implements OnInit, OnDestroy, OnChanges
             this.calculatedAgeDetail = `${years} yr${years !== 1 ? 's' : ''} ${months} mo${months !== 1 ? 's' : ''} ${days} day${days !== 1 ? 's' : ''}`;
             this.ageBreakdown = { years, months, days };
             const wasMinor = this.isMinor;
-            this.isMinor = years < 10;
+            this.isMinor = years < 18;
             this.isSeniorCitizen = years >= 60;
             // Add/remove guardian form group based on minor status
             if (this.isMinor && !wasMinor) {