tweak(app): keep file tree toggle visible

Always show the titlebar file tree button (and space the right-side icon buttons at 4px) so it stays accessible regardless of the review panel state.

packages/app/src/components/session/session-header.tsx

@@ -553,7 +553,7 @@ export function SessionHeader() {
                 </div>
               </Show>
               <div class="flex items-center gap-1">
-                <div class="hidden md:flex items-center gap-3 shrink-0">
+                <div class="hidden md:flex items-center gap-1 shrink-0">
                   <TooltipKeybind
                     title={language.t("command.terminal.toggle")}
                     keybind={command.keybind("terminal.toggle")}
@@ -585,8 +585,7 @@ export function SessionHeader() {
                       </div>
                     </Button>
                   </TooltipKeybind>
-                </div>
+
-                <div class="hidden md:block shrink-0">
                   <TooltipKeybind
                     title={language.t("command.review.toggle")}
                     keybind={command.keybind("review.toggle")}
@@ -618,23 +617,7 @@ export function SessionHeader() {
                       </div>
                     </Button>
                   </TooltipKeybind>
-                </div>
+
-                <div class="hidden md:block shrink-0">
-                  <div
-                    aria-hidden={!view().reviewPanel.opened()}
-                    class="overflow-hidden transition-[width,margin-left] duration-200 ease-out motion-reduce:transition-none"
-                    classList={{
-                      "w-8 ml-0": view().reviewPanel.opened(),
-                      "w-0 -ml-1": !view().reviewPanel.opened(),
-                    }}
-                  >
-                    <div
-                      class="transition-[opacity,transform] duration-200 ease-out origin-center motion-reduce:transition-none"
-                      classList={{
-                        "opacity-100 scale-100": view().reviewPanel.opened(),
-                        "opacity-0 scale-90": !view().reviewPanel.opened(),
-                      }}
-                    >
                   <TooltipKeybind
                     title={language.t("command.fileTree.toggle")}
                     keybind={command.keybind("fileTree.toggle")}
@@ -643,11 +626,9 @@ export function SessionHeader() {
                       variant="ghost"
                       class="titlebar-icon w-8 h-6 p-0 box-border"
                       onClick={() => layout.fileTree.toggle()}
-                          disabled={!view().reviewPanel.opened()}
                       aria-label={language.t("command.fileTree.toggle")}
                       aria-expanded={layout.fileTree.opened()}
                       aria-controls="file-tree-panel"
-                          tabIndex={view().reviewPanel.opened() ? undefined : -1}
                     >
                       <div class="relative flex items-center justify-center size-4">
                         <Icon
@@ -664,8 +645,6 @@ export function SessionHeader() {
                 </div>
               </div>
             </div>
-              </div>
-            </div>
           </Portal>
         )}
       </Show>