fix: validate tenant and lease contact details

frontend/src/app/components/tenants-page/tenants-page.css

@@ -127,6 +127,15 @@
   overflow: hidden;
   clip: rect(0 0 0 0);
 }
+.upload-action small {
+  color: var(--text-muted);
+  font-weight: 500;
+}
+.attachment-error {
+  margin: 8px 0 0;
+  color: var(--danger);
+  font-size: 0.78rem;
+}
 .card-actions {
   display: flex;
   justify-content: flex-end;