fix(linux): resolve WebKitGTK DMA-BUF rendering issue and preserve user .desktop customizations

- Set WEBKIT_DISABLE_DMABUF_RENDERER=1 at startup to fix blank screen on Debian 13.2 and Nvidia GPUs
- Only register deep-link handler on first run to avoid overwriting user customizations
- Use correct Tauri path API (app.path().data_dir()) instead of dirs::data_dir() to match plugin's actual .desktop file location

src-tauri/src/lib.rs

@@ -736,10 +736,35 @@ pub fn run() {
             // Linux 和 Windows 调试模式需要显式注册
             #[cfg(any(target_os = "linux", all(debug_assertions, windows)))]
             {
-                if let Err(e) = app.deep_link().register_all() {
-                    log::error!("✗ Failed to register deep link schemes: {}", e);
-                } else {
-                    log::info!("✓ Deep link schemes registered (Linux/Windows)");
+                #[cfg(target_os = "linux")]
+                {
+                    // Use Tauri's path API to get correct path (includes app identifier)
+                    // tauri-plugin-deep-link writes to: ~/.local/share/com.ccswitch.desktop/applications/cc-switch-handler.desktop
+                    // Only register if .desktop file doesn't exist to avoid overwriting user customizations
+                    let should_register = app
+                        .path()
+                        .data_dir()
+                        .map(|d| !d.join("applications/cc-switch-handler.desktop").exists())
+                        .unwrap_or(true);
+
+                    if should_register {
+                        if let Err(e) = app.deep_link().register_all() {
+                            log::error!("✗ Failed to register deep link schemes: {}", e);
+                        } else {
+                            log::info!("✓ Deep link schemes registered (Linux)");
+                        }
+                    } else {
+                        log::info!("⊘ Deep link handler already exists, skipping registration");
+                    }
+                }
+
+                #[cfg(all(debug_assertions, windows))]
+                {
+                    if let Err(e) = app.deep_link().register_all() {
+                        log::error!("✗ Failed to register deep link schemes: {}", e);
+                    } else {
+                        log::info!("✓ Deep link schemes registered (Windows debug)");
+                    }
                 }
             }
 

src-tauri/src/main.rs

@@ -2,5 +2,15 @@
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
 
 fn main() {
+    // 在 Linux 上设置 WebKit 环境变量以解决 DMA-BUF 渲染问题
+    // 某些 Linux 系统（如 Debian 13.2、Nvidia GPU）上 WebKitGTK 的 DMA-BUF 渲染器可能导致白屏/黑屏
+    // 参考: https://github.com/tauri-apps/tauri/issues/9394
+    #[cfg(target_os = "linux")]
+    {
+        if std::env::var("WEBKIT_DISABLE_DMABUF_RENDERER").is_err() {
+            std::env::set_var("WEBKIT_DISABLE_DMABUF_RENDERER", "1");
+        }
+    }
+
     cc_switch_lib::run();
 }