sidebar: restore jey buttons under Frappe v16

v16 removed the .collapse-sidebar-link anchor the Full Width / Switch
Theme buttons inserted before, so they silently stopped rendering.
Add a jeySidebarAnchor() helper that falls back to .body-sidebar-bottom,
and re-add a Collapse/Expand button (calls frappe.app.sidebar.toggle_width)
to replace the default v15 link Frappe dropped.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

jey_theme/public/css/shared.css

@@ -254,7 +254,8 @@ input.list-header-checkbox:checked::after {
    ========================================================================== */
 
 .jey-fullwidth-link,
-.jey-theme-switch-link {
+.jey-theme-switch-link,
+.jey-collapse-link {
         text-decoration: none;
         font-size: var(--text-sm);
         display: flex;
@@ -264,13 +265,15 @@ input.list-header-checkbox:checked::after {
 }
 
 .jey-fullwidth-link svg,
-.jey-theme-switch-link svg {
+.jey-theme-switch-link svg,
+.jey-collapse-link svg {
         margin: 0;
         flex: 0 0 auto;
 }
 
 .jey-fullwidth-link span,
-.jey-theme-switch-link span {
+.jey-theme-switch-link span,
+.jey-collapse-link span {
         margin-left: 10px;
         overflow: hidden;
         text-overflow: ellipsis;

jey_theme/public/js/jey_theme.js

@@ -651,9 +651,20 @@
 (function () {
 	"use strict";
 
+	// Frappe v15 had a "Collapse" link we inserted before; v16 removed it.
+	// Fall back to body-sidebar-bottom as the parent in v16.
+	window.jeySidebarAnchor = window.jeySidebarAnchor || function () {
+		var v15 = document.querySelector(".collapse-sidebar-link");
+		if (v15) return { parent: v15.parentNode, before: v15 };
+		var bottom = document.querySelector(".body-sidebar .body-sidebar-bottom");
+		if (bottom) return { parent: bottom, before: bottom.firstChild };
+		return null;
+	};
+
 	function addFullWidthButton() {
-		var collapse = document.querySelector(".collapse-sidebar-link");
+		if (document.querySelector(".jey-fullwidth-link")) return;
-		if (!collapse || document.querySelector(".jey-fullwidth-link")) return;
+		var anchor = window.jeySidebarAnchor();
+		if (!anchor) return;
 
 		var link = document.createElement("a");
 		link.className = "jey-fullwidth-link";
@@ -670,7 +681,7 @@
 		});
 
 		updateIcon();
-		collapse.parentNode.insertBefore(link, collapse);
+		anchor.parent.insertBefore(link, anchor.before);
 	}
 
 	$(document).ready(addFullWidthButton);
@@ -685,8 +696,9 @@
 	"use strict";
 
 	function addThemeSwitchButton() {
-		var collapse = document.querySelector(".collapse-sidebar-link");
+		if (document.querySelector(".jey-theme-switch-link")) return;
-		if (!collapse || document.querySelector(".jey-theme-switch-link")) return;
+		var anchor = window.jeySidebarAnchor && window.jeySidebarAnchor();
+		if (!anchor) return;
 
 		var link = document.createElement("a");
 		link.className = "jey-theme-switch-link";
@@ -698,13 +710,64 @@
 			new frappe.ui.ThemeSwitcher().show();
 		});
 
-		collapse.parentNode.insertBefore(link, collapse);
+		anchor.parent.insertBefore(link, anchor.before);
 	}
 
 	$(document).ready(addThemeSwitchButton);
 	$(document).on("page-change", addThemeSwitchButton);
 })();
 
+/* ==========================================================================
+   Collapse / Expand Sidebar button (restored; v16 removed the default)
+   ========================================================================== */
+
+(function () {
+	"use strict";
+
+	function isExpanded() {
+		var c = document.querySelector(".body-sidebar-container");
+		return !!(c && c.classList.contains("expanded"));
+	}
+
+	function render(link) {
+		var expanded = isExpanded();
+		var iconName = expanded ? "chevrons-left" : "chevrons-right";
+		var label = expanded ? __("Collapse Sidebar") : __("Expand Sidebar");
+		link.innerHTML =
+			frappe.utils.icon(iconName, "sm", "", "", "text-ink-gray-7 current-color", true) +
+			"<span>" + label + "</span>";
+	}
+
+	function addCollapseButton() {
+		if (document.querySelector(".jey-collapse-link")) return;
+		var anchor = window.jeySidebarAnchor && window.jeySidebarAnchor();
+		if (!anchor) return;
+
+		var link = document.createElement("a");
+		link.className = "jey-collapse-link";
+		render(link);
+
+		link.addEventListener("click", function () {
+			if (frappe.app && frappe.app.sidebar && frappe.app.sidebar.toggle_width) {
+				frappe.app.sidebar.toggle_width();
+			}
+			// toggle_width updates class synchronously; re-render
+			render(link);
+		});
+
+		anchor.parent.insertBefore(link, anchor.before);
+
+		// Keep label in sync if sidebar state changes elsewhere
+		$(document).off("sidebar-expand.jey-collapse").on("sidebar-expand.jey-collapse", function () {
+			var el = document.querySelector(".jey-collapse-link");
+			if (el) render(el);
+		});
+	}
+
+	$(document).ready(addCollapseButton);
+	$(document).on("page-change", addCollapseButton);
+})();
+
 /* ==========================================================================
    Hide "Website" item from sidebar user dropdown
    ========================================================================== */