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/edit-client/contact-otp-block/contact-otp-block.component.html

@@ -0,0 +1,76 @@
+<!--
+  Copyright since 2025 Mifos Initiative
+
+  This Source Code Form is subject to the terms of the Mozilla Public
+  License, v. 2.0. If a copy of the MPL was not distributed with this
+  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+-->
+
+<div class="cotp-block" [class.cotp-block--verified]="verified">
+  <div class="cotp-block__header">
+    <span class="cotp-block__label">{{ label }}</span>
+    <span class="cotp-block__target">{{ maskedDestination }}</span>
+  </div>
+
+  @if (verified) {
+    <div class="cotp-block__verified">
+      <fa-icon icon="check-circle"></fa-icon>
+      <span>Verified</span>
+    </div>
+  } @else if (!otpSent) {
+    <button type="button" class="cotp-btn cotp-btn--primary" (click)="sendOtp()" [disabled]="sending || !destination">
+      @if (sending) {
+        <mat-progress-spinner diameter="16" mode="indeterminate"></mat-progress-spinner>
+        <span>Sending…</span>
+      } @else {
+        <fa-icon icon="paper-plane"></fa-icon>
+        <span>Send OTP</span>
+      }
+    </button>
+  } @else {
+    <div class="cotp-otp">
+      @for (i of digitIndexes; track i) {
+        <input
+          #digitBox
+          type="text"
+          inputmode="numeric"
+          maxlength="1"
+          class="cotp-otp__box"
+          [value]="digitControls[i].value"
+          [attr.autocomplete]="i === 0 ? 'one-time-code' : 'off'"
+          (input)="onDigitInput(i, $any($event.target).value)"
+          (keydown)="onDigitKeydown(i, $event)"
+          (paste)="onDigitPaste($event)"
+        />
+      }
+    </div>
+
+    <div class="cotp-block__actions">
+      <button
+        type="button"
+        class="cotp-btn cotp-btn--primary"
+        (click)="verifyOtp()"
+        [disabled]="!codeValid || verifying"
+      >
+        @if (verifying) {
+          <mat-progress-spinner diameter="16" mode="indeterminate"></mat-progress-spinner>
+          <span>Verifying…</span>
+        } @else {
+          <fa-icon icon="check-circle"></fa-icon>
+          <span>Verify</span>
+        }
+      </button>
+      <button type="button" class="cotp-btn cotp-btn--ghost" (click)="resendOtp()" [disabled]="resendCountdown > 0">
+        <fa-icon icon="redo"></fa-icon>
+        <span>{{ resendCountdown > 0 ? 'Resend (' + resendCountdown + 's)' : 'Resend OTP' }}</span>
+      </button>
+    </div>
+  }
+
+  @if (errorMessage) {
+    <div class="cotp-error">
+      <fa-icon icon="exclamation-circle"></fa-icon>
+      {{ errorMessage }}
+    </div>
+  }
+</div>