feat: MFA/2FA, OTP audit logs, KYC + client/user enhancements

- Access Control module: SMS/Email/TOTP/Hardware-token MFA factor management
- OTP Audit Logs module under Admin menu (list + detail) with 401/403 handling
- Two-factor authentication login flow updates
- Client KYC, India address, family-members, ckyc, nominee enhancements
- New shared KYC helpers (kyc-proof-types, kyc-upload-helper.service)
- User create/edit/view enhancements
- Shell navigation: OTP Audit Logs entry under real Admin menu

src/app/shared/styles/list-layout.scss

@@ -456,6 +456,11 @@ $mono: 'Roboto Mono', 'DM Mono', monospace;
   color: #475569;
 }
 
+.cell-empty {
+  color: #94a3b8;
+  font-style: italic;
+}
+
 // ===== Status Badge =====
 .status-badge {
   display: inline-flex;