feat(portal): mobile sidebar hamburger toggle (vanilla JS)

20 lines, no framework. Toggles .o_fp_open on sidebar + backdrop.
Backdrop click closes drawer; navigating a sidebar link on mobile
auto-closes. No-ops gracefully when sidebar isn't on the page
(logged-out, 500 pages, etc.).

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

fusion_plating/fusion_plating_portal/static/src/js/fp_portal_sidebar.js

@@ -0,0 +1,48 @@
+/**
+ * Fusion Plating — Portal sidebar hamburger toggle.
+ * Vanilla JS — no OWL / no jQuery. Loaded on every /my/* page.
+ * Below 768px the sidebar is translateX(-100%); toggling
+ * .o_fp_open on both sidebar + backdrop shows/hides it.
+ */
+(function () {
+    "use strict";
+
+    function init() {
+        var sidebar = document.querySelector(".o_fp_portal_sidebar");
+        var hamburger = document.querySelector(".o_fp_portal_hamburger");
+        var backdrop = document.querySelector(".o_fp_portal_backdrop");
+        if (!sidebar || !hamburger || !backdrop) {
+            return; // sidebar not on this page (logged-out, error pages, etc.)
+        }
+
+        function toggleOpen(force) {
+            var willOpen = (typeof force === "boolean")
+                ? force
+                : !sidebar.classList.contains("o_fp_open");
+            sidebar.classList.toggle("o_fp_open", willOpen);
+            backdrop.classList.toggle("o_fp_open", willOpen);
+        }
+
+        hamburger.addEventListener("click", function (e) {
+            e.preventDefault();
+            toggleOpen();
+        });
+        backdrop.addEventListener("click", function () {
+            toggleOpen(false);
+        });
+        // Close when navigating to a sidebar link on mobile
+        sidebar.querySelectorAll("a.o_fp_sidebar_item").forEach(function (a) {
+            a.addEventListener("click", function () {
+                if (window.innerWidth < 769) {
+                    toggleOpen(false);
+                }
+            });
+        });
+    }
+
+    if (document.readyState === "loading") {
+        document.addEventListener("DOMContentLoaded", init);
+    } else {
+        init();
+    }
+})();