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/client-stepper/client-general-step/client-general-step.component.scss

@@ -1493,6 +1493,21 @@ form {
   }
 }
 
+/* Create-time mobile/email OTP verification — spans both `.form-grid` columns so the two
+ * blocks sit on their own full-width row instead of disrupting the field/verify-button pairing
+ * above them. */
+.contact-otp-row {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 16px;
+  grid-column: 1 / -1;
+  margin-top: 4px;
+
+  mifosx-client-contact-otp-block {
+    flex: 1 1 260px;
+  }
+}
+
 @media (width <= 768px) {
   .form-grid {
     grid-template-columns: 1fr;
@@ -1516,6 +1531,10 @@ form {
       max-width: none;
     }
   }
+
+  .contact-otp-row {
+    flex-direction: column;
+  }
 }
 
 .guardian-card__avatar.has-photo {