feat(clients): maker-checker for client edits (frontend)

- New "Pending Client Edits" screen under Checker Inbox & Tasks: server-driven pagination,
  date range + Today/Yesterday/All presets, status filter (Pending/Approved/Rejected), search —
  mirrors ChequebookRequestsComponent's architecture.
- Compare dialog diffs the maker's proposed values against a point-in-time "before" snapshot
  (client-edit-diff.util.ts) captured when the edit page was opened, so only genuinely changed
  fields show — works correctly for Pending, Approved, and Rejected edits alike, since it no
  longer depends on comparing against the live (possibly already-updated) client record.
- edit-client.component.ts: General tab save now submits for approval instead of applying
  immediately, shows a pending-approval banner, and blocks a second submission while one's
  outstanding.
- error-handler.interceptor.ts: added the new /clients/{id}/edit/pending check to the existing
  "expected 403/404, don't alert" allowlist (same pattern already used for client images/KYC).

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

src/app/clients/edit-client/edit-client.component.scss

@@ -217,6 +217,26 @@
   }
 }
 
+/* ─── Pending Edit Approval Banner ─── */
+.pending-edit-banner {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  padding: 12px 16px;
+  margin: 0 0 16px;
+  background: #eff6ff;
+  border: 1px solid #93c5fd;
+  border-radius: 8px;
+  color: #1e40af;
+  font-size: 13px;
+  font-weight: 500;
+
+  mat-icon {
+    color: #2563eb;
+    flex-shrink: 0;
+  }
+}
+
 /* ─── Re-KYC Alert Banner ─── */
 .rekyc-alert {
   display: flex;