feat: shadcn -> rust-ui.com migration + TorrentDetail silme

- Tüm leptos-shadcn-* paketleri kaldırıldı (19 dependency)
- leptos_ui, tw_merge, strum eklendi
- components/ui/ modülü oluşturuldu (Button, Card, Input)
- TorrentDetail bileşeni tamamen silindi
- sidebar.rs: saf HTML+Tailwind ile SidebarButton yardımcı bileşeni
- toolbar.rs, login.rs, setup.rs, add_torrent.rs: saf HTML+Tailwind
- table.rs: shadcn Card -> rust-ui Card
- app.rs: Skeleton -> animate-pulse div

frontend/Cargo.toml

@@ -35,22 +35,7 @@ thiserror = "2.0"
 rmp-serde = "1.3"
 struct-patch = "0.5"
 
-# ShadCN UI Components (Individual)
-leptos-shadcn-button = "0.8"
-leptos-shadcn-input = "0.8"
-leptos-shadcn-card = "0.8"
-leptos-shadcn-badge = "0.8"
-leptos-shadcn-context-menu = "0.8"
-leptos-shadcn-separator = "0.8"
-leptos-shadcn-progress = "0.8"
-leptos-shadcn-avatar = "0.8"
-leptos-shadcn-sheet = "0.8"
-leptos-shadcn-tabs = "0.8"
-leptos-shadcn-scroll-area = "0.8"
-leptos-shadcn-dialog = "0.8"
-leptos-shadcn-label = "0.8"
-leptos-shadcn-alert = "0.8"
-
-leptos-shadcn-dropdown-menu = "0.8"
-leptos-shadcn-tooltip = "0.8"
-leptos-shadcn-skeleton = "0.8"
+# Rust/UI Components
+leptos_ui = "0.3"
+tw_merge = "0.1"
+strum = { version = "0.26", features = ["derive"] }