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.scss

@@ -0,0 +1,177 @@
+/**
+ * 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/.
+ */
+
+/* Card with 6 individually-bordered digit boxes (not the single-input/background-gradient
+ * trick used elsewhere in this app) — each box is its own <input>, so focus/border state is
+ * per-digit rather than shared across the whole code. */
+
+:host {
+  display: block;
+}
+
+.cotp-block {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 20px;
+  padding: 28px 24px;
+  border: 1px solid #e7ecf3;
+  border-radius: 18px;
+  background: #fff;
+  box-shadow: 0 8px 24px -8px rgb(15 23 42 / 10%);
+  text-align: center;
+
+  &--verified {
+    border-color: #86efac;
+    background: #f7fdf9;
+  }
+}
+
+.cotp-block__header {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+}
+
+.cotp-block__label {
+  font-size: 15px;
+  font-weight: 800;
+  text-transform: uppercase;
+  letter-spacing: 0.4px;
+  color: #1e293b;
+}
+
+.cotp-block__target {
+  font-size: 15px;
+  font-weight: 700;
+  color: #1074b9;
+  word-break: break-all;
+}
+
+.cotp-block__verified {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+  padding: 7px 16px;
+  border-radius: 999px;
+  background: #dcfce7;
+  color: #15803d;
+  font-size: 13px;
+  font-weight: 700;
+}
+
+.cotp-block__actions {
+  display: flex;
+  justify-content: center;
+  gap: 12px;
+  width: 100%;
+}
+
+.cotp-otp {
+  display: flex;
+  justify-content: center;
+  gap: 10px;
+}
+
+.cotp-otp__box {
+  box-sizing: border-box;
+  width: 46px;
+  height: 52px;
+  border: 1.5px solid #dde3ec;
+  border-radius: 12px;
+  background: #fff;
+  color: #0f172a;
+  font-family: 'SF Mono', 'Cascadia Code', Consolas, monospace;
+  font-size: 22px;
+  font-weight: 700;
+  text-align: center;
+  caret-color: #1074b9;
+  outline: none;
+  transition:
+    border-color 0.15s,
+    box-shadow 0.15s;
+
+  &:hover {
+    border-color: #b7c2d0;
+  }
+
+  &:focus {
+    border-color: #1074b9;
+    box-shadow: 0 0 0 3px rgb(16 116 185 / 15%);
+  }
+}
+
+.cotp-btn {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  gap: 8px;
+  flex: 1 1 0;
+  height: 48px;
+  padding: 0 20px;
+  border-radius: 999px;
+  font-size: 14px;
+  font-weight: 700;
+  cursor: pointer;
+  border: 1.5px solid transparent;
+  transition:
+    background 0.15s,
+    border-color 0.15s,
+    color 0.15s,
+    opacity 0.15s;
+
+  &:disabled {
+    cursor: not-allowed;
+    opacity: 0.55;
+  }
+
+  &--primary {
+    background: #1074b9;
+    color: #fff;
+    box-shadow: 0 6px 16px -4px rgb(16 116 185 / 45%);
+
+    &:hover:not(:disabled) {
+      background: #0d5f96;
+    }
+  }
+
+  &--ghost {
+    background: #fff;
+    color: #1074b9;
+    border-color: #cfe0ee;
+
+    &:hover:not(:disabled) {
+      border-color: #1074b9;
+      background: #f0f7fc;
+    }
+  }
+
+  mat-progress-spinner ::ng-deep circle {
+    stroke: currentcolor !important;
+  }
+}
+
+.cotp-error {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px 14px;
+  border-radius: 10px;
+  background: #fef2f2;
+  border: 1px solid #fecaca;
+  color: #b91c1c;
+  font-size: 12.5px;
+}
+
+@media (width <= 420px) {
+  .cotp-otp__box {
+    width: 38px;
+    height: 46px;
+    font-size: 18px;
+  }
+}