feat(ui): 接入 vendor 真实图标库 + 图标选择器

- assets/icons/ 共 80+ 张真实品牌图标嵌入 UI 包
- entry 新增 IconKey 字段，持久化到 config.Entry.IconName
- iconPickerDialog 网格布局图标选择器
- Add 完成后自动弹出图标选择器，Skip 则用 vendor 占位图
- ⋯ 菜单新增 "Change icon..." 项
- vendorIconFor 解析顺序：catalog → vendor 占位 → qr 兜底

internal/ui/row_menu.go

@@ -18,6 +18,7 @@ const (
 	rowActionDelete
 	rowActionMoveUp
 	rowActionMoveDown
+	rowActionChangeIcon
 )
 
 // rowActionMenu is the small popup opened by the ⋯ button on each entry
@@ -29,11 +30,12 @@ type rowActionMenu struct {
 	canMoveUp   bool
 	canMoveDown bool
 
-	renameBtn   widget.Clickable
-	deleteBtn   widget.Clickable
-	moveUpBtn   widget.Clickable
-	moveDownBtn widget.Clickable
-	cancelBtn   widget.Clickable
+	renameBtn     widget.Clickable
+	deleteBtn     widget.Clickable
+	moveUpBtn     widget.Clickable
+	moveDownBtn   widget.Clickable
+	changeIconBtn widget.Clickable
+	cancelBtn     widget.Clickable
 }
 
 func newRowActionMenu(idx, total int) *rowActionMenu {
@@ -61,6 +63,8 @@ func (m *rowActionMenu) Pick(gtx layout.Context) (rowAction, bool) {
 			return rowActionNone, false
 		}
 		return rowActionMoveDown, true
+	case m.changeIconBtn.Clicked(gtx):
+		return rowActionChangeIcon, true
 	case m.cancelBtn.Clicked(gtx):
 		return rowActionNone, true
 	}
@@ -102,6 +106,7 @@ func (m *rowActionMenu) Layout(gtx layout.Context, th *material.Theme) layout.Di
 					layout.Rigid(layout.Spacer{Height: unit.Dp(12)}.Layout),
 					row(&m.renameBtn, i18n.T("action_rename"), true),
 					row(&m.deleteBtn, i18n.T("action_delete"), true),
+					row(&m.changeIconBtn, i18n.T("action_change_icon"), true),
 					row(&m.moveUpBtn, i18n.T("action_move_up"), m.canMoveUp),
 					row(&m.moveDownBtn, i18n.T("action_move_down"), m.canMoveDown),
 					layout.Rigid(layout.Spacer{Height: unit.Dp(8)}.Layout),