ui: reorder bookmarks bar buttons

- Change button order to: Home, Explore, Settings
- Maintains all existing functionality

src/components/SidebarHeader.tsx

@@ -141,18 +141,6 @@ const SidebarHeader: React.FC<SidebarHeaderProps> = ({ onToggleCollapse, onLogou
             ariaLabel="Home"
             variant="ghost"
           />
-          <IconButton
-            icon={faGear}
-            onClick={() => {
-              if (isMobile) {
-                onToggleCollapse()
-              }
-              onOpenSettings()
-            }}
-            title="Settings"
-            ariaLabel="Settings"
-            variant="ghost"
-          />
           <IconButton
             icon={faPersonHiking}
             onClick={() => {
@@ -165,6 +153,18 @@ const SidebarHeader: React.FC<SidebarHeaderProps> = ({ onToggleCollapse, onLogou
             ariaLabel="Explore"
             variant="ghost"
           />
+          <IconButton
+            icon={faGear}
+            onClick={() => {
+              if (isMobile) {
+                onToggleCollapse()
+              }
+              onOpenSettings()
+            }}
+            title="Settings"
+            ariaLabel="Settings"
+            variant="ghost"
+          />
           {!isMobile && (
             <button 
               onClick={onToggleCollapse}