Keep sidebar controls in dedicated left rail

public/app.ts

@@ -53,6 +53,7 @@ const darkContrastSelect = document.querySelector("#darkContrastSelect");
 const catalogScreen = document.querySelector(".catalog-screen");
 const secondaryPanelToggle = document.querySelector("#secondaryPanelToggle");
 const mainWorkspaceToggle = document.querySelector("#mainWorkspaceToggle");
+let sidebarUserClosed = false;
 
 const nativeFetch = window.fetch.bind(window);
 window.fetch = (input, init = {}) => {
@@ -225,7 +226,6 @@ darkContrastSelect.addEventListener("change", saveAppearance);
 
 loadDatabaseMode();
 syncSidebarForViewport();
-window.matchMedia("(min-width: 981px)").addEventListener("change", syncSidebarForViewport);
 
 setTimeout(() => {
   if (manufacturerSelect.value) {
@@ -940,11 +940,12 @@ function toggleParserDrawer() {
 }
 
 function syncSidebarForViewport() {
-  if (window.matchMedia("(min-width: 981px)").matches) openSidebar();
+  if (window.matchMedia("(min-width: 981px)").matches && !sidebarUserClosed) openSidebar();
   else closeSidebar();
 }
 
 function openSidebar() {
+  sidebarUserClosed = false;
   sidebarDrawer.classList.add("is-open");
   sidebarOverlay.hidden = false;
   sidebarOpenButton.hidden = true;
@@ -954,6 +955,7 @@ function openSidebar() {
 }
 
 function closeSidebar() {
+  sidebarUserClosed = true;
   sidebarDrawer.classList.remove("is-open");
   sidebarOverlay.hidden = true;
   sidebarOpenButton.hidden = false;