feat(clients): dual-OTP contact-change verification, webcam signature capture, and client history tab

Frontend counterpart to the backend dual-OTP contact-change feature:

- New ContactOtpBlockComponent (6-box segmented OTP input) used up to 4x in
  Edit Client (old/new mobile, old/new email — grouped under per-field
  sub-headers) and once each for mobile/email in Create Client, gating
  Save/Save & Next until every required box is verified.
- edit-client.component.ts: detects mobile/email/DOB changes against the
  loaded snapshot using local-date comparison (not `.toISOString()`, which
  false-triggers a day-shift in positive-UTC-offset timezones) and
  trimmed/case-insensitive email comparison (autofill whitespace or re-typed
  casing no longer reads as a change the masked preview can't explain).
- client-kyc-step.component.ts: new `invalidFieldLabels` getter names every
  currently-invalid required KYC field, surfaced via the Save & Next tooltip
  in both create-client and edit-client so a greyed-out button always
  explains what's still missing instead of a generic message.
- CaptureImageDialogComponent generalized for both profile photo and
  signature (photograph-a-paper-signature) capture:
  - Frame aspect now matches the requested getUserMedia resolution
    (4:3 profile / 16:9 signature) with object-fit: cover, eliminating the
    pillarboxing (black bars) a mismatched box previously caused.
  - Suppresses Chromium's auto-injected PiP/cast corner overlay icons.
  - Frame height capped in vh (not just px) so the dialog fits short
    viewports instead of pushing Cancel/Upload below the fold.
- upload-document-dialog.component.ts: generic Documents-tab upload now also
  offers "Capture from Webcam" alongside Browse, reusing the same capture
  dialog.
- New client History tab (reuses the existing Audit Trail data, scoped to
  this client) and dataUrlToFile/dataUrlToBlob util for routing webcam
  captures through the same upload pipelines as a picked file.

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

src/app/clients/clients-view/clients-view.component.html

@@ -426,6 +426,9 @@
     <button mat-menu-item (click)="doAction('Upload Signature')" *mifosxHasPermission="'CREATE_CLIENTIMAGE'">
       {{ 'labels.buttons.Upload Signature' | translate }}
     </button>
+    <button mat-menu-item (click)="doAction('Capture Signature')" *mifosxHasPermission="'CREATE_CLIENTIMAGE'">
+      Capture Signature (Webcam)
+    </button>
     <button mat-menu-item (click)="doAction('Delete Signature')" *mifosxHasPermission="'DELETE_CLIENTIMAGE'">
       {{ 'labels.buttons.Delete Signature' | translate }}
     </button>
@@ -559,6 +562,15 @@
       >
         <i class="fa fa-sticky-note cv-tab-icon"></i> {{ 'labels.inputs.Notes' | translate }}
       </a>
+      <a
+        mat-tab-link
+        [routerLink]="['./history']"
+        routerLinkActive
+        #history="routerLinkActive"
+        [active]="history.isActive"
+      >
+        <i class="fa fa-history cv-tab-icon"></i> History
+      </a>
       @for (clientDatatable of clientDatatables; track clientDatatable) {
         <a
           mat-tab-link