feat: optimize file icons, UI, share direct links, and upload performance

- Replace CSS-only file icons with SVG icons for each file type (folder, image, video, audio, archive, document, app)
- Add navigation icons to left sidebar (Baidu Netdisk style)
- Enlarge file cards (108px -> 120px) with smoother transitions
- Add direct links section to share page with copy/delete actions
- Add Rust bridge commands for fetching and deleting direct links
- Optimize local storage put() to use rename-first strategy instead of copyFileSync for instant large file completion
- Show "server processing" status during upload finalization instead of appearing stuck

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

desktop-client/src-tauri/src/lib.rs

@@ -1032,6 +1032,39 @@ async fn api_get_my_shares(
     .await
 }
 
+#[tauri::command]
+async fn api_get_my_direct_links(
+    state: tauri::State<'_, ApiState>,
+    base_url: String,
+) -> Result<BridgeResponse, String> {
+    request_with_optional_csrf(
+        &state.client,
+        Method::GET,
+        &base_url,
+        "/api/direct-link/my",
+        None,
+        false,
+    )
+    .await
+}
+
+#[tauri::command]
+async fn api_delete_direct_link(
+    state: tauri::State<'_, ApiState>,
+    base_url: String,
+    link_id: i64,
+) -> Result<BridgeResponse, String> {
+    request_with_optional_csrf(
+        &state.client,
+        Method::DELETE,
+        &base_url,
+        &format!("/api/direct-link/{}", link_id),
+        None,
+        false,
+    )
+    .await
+}
+
 #[tauri::command]
 async fn api_create_share(
     state: tauri::State<'_, ApiState>,
@@ -2074,6 +2107,8 @@ pub fn run() {
             api_delete_file,
             api_get_download_url,
             api_get_my_shares,
+            api_get_my_direct_links,
+            api_delete_direct_link,
             api_create_share,
             api_delete_share,
             api_create_direct_link,