fix: clean up empty catch blocks in UI hooks and components

修复了 5 个 UI 组件和 hooks 中的空 catch 块：
- useDragToSystemDesktop.ts: 修复 2 个空 catch 块
- HomepageAuth.tsx: 修复 1 个空 catch 块
- HostManagerEditor.tsx: 修复 2 个空 catch 块

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

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

src/ui/hooks/useDragToSystemDesktop.ts

@@ -59,7 +59,9 @@ export function useDragToSystemDesktop({
           };
         });
       }
-    } catch (error) {}
+    } catch {
+      // IndexedDB not available or failed to retrieve directory
+    }
     return null;
   };
 
@@ -75,7 +77,9 @@ export function useDragToSystemDesktop({
           store.put({ handle: dirHandle }, "lastSaveDir");
         };
       }
-    } catch (error) {}
+    } catch {
+      // Failed to save directory handle
+    }
   };
 
   const isFileSystemAPISupported = () => {