fix: clean up empty catch blocks in frontend components

修复了前端组件中的空 catch 块：
- Tunnel.tsx: 修复空 catch 块并添加注释
- ServerConfig.tsx: 修复空 catch 块并添加注释
- TerminalKeyboard.tsx: 修复空 catch 块并添加注释
- system-crypto.ts: 修复遗漏的空 catch 块

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/ui/Mobile/Apps/Terminal/TerminalKeyboard.tsx

@@ -110,7 +110,9 @@ export function TerminalKeyboard({
         if (navigator.vibrate) {
           navigator.vibrate(20);
         }
-      } catch (e) {}
+      } catch {
+        // Ignore vibration errors on unsupported devices
+      }
 
       onSendInput(input);
     },