v1.0.0

Add password management features and UI enhancements

- Added `CreatePasswordAsync` and `DeletePasswordByIndexAsync` methods to `ApiService.cs` for creating and deleting passwords via API.
- Updated `EncryptionHelper.cs` to handle potential null values for `Key` and `Iv` and made minor code improvements.
- Modified `MainForm.Designer.cs` to add new UI elements (`textBox1`, `textBox2`, `textBox3`, `button2`) and adjusted the layout of existing elements.
- Updated `MainForm.cs` to handle new button click events for adding and deleting passwords, and to show/hide the delete button based on the selection in the data grid.
- Added functionality to `button2_Click` in `MainForm.cs` to open the local application data folder in Windows Explorer.