portal agent: add foldable/folded support classes (#25922)

data/themes/gadjo/static/css/agent-portal.scss

@@ -139,6 +139,32 @@ div.links-list {
 	}
 }
 
+/* support foldable cells */
+div.cell {
+	&.foldable {
+		> div > h2:first-child {
+			&::after {
+				font-family: FontAwesome;
+				content: "\f106"; /* angle-up */
+				position: absolute;
+				right: 1em;
+			}
+			cursor: pointer;
+		}
+	}
+	&.foldable.folded {
+		> div > h2:first-child {
+			display: block;
+			&::after {
+				content: "\f107"; /* angle-down */
+			}
+		}
+		> div > * {
+			display: none;
+		}
+	}
+}
+
 @media screen and (min-width: 1586px) {
 	div#page-content div.cubesbarchart {
 		width: 49.5%;