Refactor sidebar layout and button functionality in App.tsx

src/App.tsx

@@ -1357,9 +1357,8 @@ export default function App() {
 
   return (
     <div className={`app app--theme-${theme}${sidebarCollapsed ? " app--sidebar-collapsed" : ""}`}>
-      <aside className={`sidebar${sidebarCollapsed ? " sidebar--collapsed" : ""}`}>
       {!sidebarCollapsed ? (
-          <>
+        <aside className="sidebar">
           <div className="sidebar__header">
             <div className="sidebar__title-row">
               <div className="app-title">TextDB</div>
@@ -1390,21 +1389,7 @@ export default function App() {
               )}
             </div>
           </div>
-          </>
+          <div className="sidebar__footer">
-        ) : null}
-        <div className={`sidebar__footer${sidebarCollapsed ? " sidebar__footer--collapsed" : ""}`}>
-          {sidebarCollapsed ? (
-            <button
-              className="icon-button"
-              onClick={() => setSidebarCollapsed(false)}
-              aria-label="Expand sidebar"
-              title="Expand sidebar"
-              type="button"
-            >
-              <span className="icon-button__glyph" aria-hidden="true">▶</span>
-            </button>
-          ) : (
-            <>
             <button
               className="icon-button"
               onClick={handleNewFolder}
@@ -1450,10 +1435,9 @@ export default function App() {
             >
               <span className="icon-button__glyph" aria-hidden="true">◀</span>
             </button>
-            </>
-          )}
           </div>
         </aside>
+      ) : null}
 
       <main className="workspace">
         <div className="workspace__body">
@@ -1543,6 +1527,17 @@ export default function App() {
               </div>
 
               <div className="editor__footer">
+                {sidebarCollapsed ? (
+                  <button
+                    className="icon-button"
+                    onClick={() => setSidebarCollapsed(false)}
+                    aria-label="Expand sidebar"
+                    title="Expand sidebar"
+                    type="button"
+                  >
+                    <span className="icon-button__glyph" aria-hidden="true">▶</span>
+                  </button>
+                ) : null}
                 {hasText ? (
                   <>
                     <button