feat: implement collapsible sidebar

frontend/src/components/layout/toolbar.rs

@@ -7,11 +7,25 @@ use crate::components::ui::dialog::{Dialog, DialogContent, DialogTrigger};
 use crate::components::layout::sidebar::Sidebar;
 
 #[component]
-pub fn Toolbar() -> impl IntoView {
+pub fn Toolbar(
+    #[prop(into)] on_toggle_sidebar: Callback<()>,
+) -> impl IntoView {
     view! {
         <div class="flex min-h-14 h-auto items-center border-b border-border bg-background px-4" style="padding-top: env(safe-area-inset-top);">
             // Sol kısım: Menü butonu (Mobil) + Add Torrent
             <div class="flex items-center gap-3">
+                // Desktop Toggle Button
+                <div class="hidden lg:block">
+                    <Button
+                        variant=ButtonVariant::Ghost
+                        size=ButtonSize::Icon
+                        class="size-9"
+                        on:click=move |_| on_toggle_sidebar.run(())
+                    >
+                        <PanelLeft class="size-5" />
+                        <span class="hidden">"Menüyü Daralt/Genişlet"</span>
+                    </Button>
+                </div>
                 
                 // --- MOBILE SHEET (SIDEBAR) ---
                 <div class="lg:hidden">