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-routing.module.ts

@@ -22,6 +22,7 @@ import { AddFamilyMemberComponent } from './clients-view/family-members-tab/add-
 import { EditFamilyMemberComponent } from './clients-view/family-members-tab/edit-family-member/edit-family-member.component';
 import { IdentitiesTabComponent } from './clients-view/identities-tab/identities-tab.component';
 import { NotesTabComponent } from './clients-view/notes-tab/notes-tab.component';
+import { HistoryTabComponent } from './clients-view/history-tab/history-tab.component';
 import { DocumentsTabComponent } from './clients-view/documents-tab/documents-tab.component';
 import { DatatableTabComponent } from './clients-view/datatable-tab/datatable-tab.component';
 import { AddressTabComponent } from './clients-view/address-tab/address-tab.component';
@@ -208,6 +209,11 @@ const routes: Routes = [
                 clientNotes: ClientNotesResolver
               }
             },
+            {
+              path: 'history',
+              component: HistoryTabComponent,
+              data: { title: 'History', breadcrumb: 'History', routeParamBreadcrumb: false }
+            },
             {
               path: 'datatables',
               children: [