feat(ui): 开机自启动 + 窗口大小记忆

- win32/autostart: SetAutoStart/IsAutoStartEnabled 操作 HKCU Run 键
- win32/window_size: GetWindowSize 通过 GetWindowRect 获取窗口尺寸
- config: 新增 AutoStart、WindowWidth、WindowHeight 字段
- store: Preferences/SetPreferences 扩展支持 autoStart + windowSize
- dialog_preferences: 新增"开机自启动"复选框
- app.go: 启动时恢复窗口大小，关闭时通过 SetWindowSize 保存
- i18n: label_auto_start / hint_auto_start 三语翻译

internal/config/model.go

@@ -30,8 +30,15 @@ type Config struct {
 	AutoLockMinutes int `yaml:"auto_lock_minutes,omitempty" json:"auto_lock_minutes,omitempty"`
 	// MinimizeToTray sends the window to the system tray instead of
 	// exiting when the close button is pressed.
-	MinimizeToTray bool    `yaml:"minimize_to_tray,omitempty" json:"minimize_to_tray,omitempty"`
-	Encrypted      bool    `yaml:"encrypted" json:"encrypted"`
-	EncryptedBlob  string  `yaml:"encrypted_blob,omitempty" json:"encrypted_blob,omitempty"`
-	Entries        []Entry `yaml:"entries,omitempty" json:"entries,omitempty"`
+	MinimizeToTray bool `yaml:"minimize_to_tray,omitempty" json:"minimize_to_tray,omitempty"`
+	// AutoStart registers the application to launch at Windows logon
+	// via the HKCU Run key.
+	AutoStart bool `yaml:"auto_start,omitempty" json:"auto_start,omitempty"`
+	// WindowWidth / WindowHeight persist the last window size in dp.
+	// Zero means "use the default 560×420".
+	WindowWidth   int     `yaml:"window_width,omitempty" json:"window_width,omitempty"`
+	WindowHeight  int     `yaml:"window_height,omitempty" json:"window_height,omitempty"`
+	Encrypted     bool    `yaml:"encrypted" json:"encrypted"`
+	EncryptedBlob string  `yaml:"encrypted_blob,omitempty" json:"encrypted_blob,omitempty"`
+	Entries       []Entry `yaml:"entries,omitempty" json:"entries,omitempty"`
 }