feat(ui): 条目管理增强 — 重命名/删除/重排序

每行右侧增加 ⋯ 按钮，弹出菜单支持重命名、删除、上移、下移。
- renameEntry / deleteEntry / moveEntry 三个 appState 方法
- rowActionMenu 弹出菜单 + renameDialog + confirmDeleteDialog
- 删除自动注销快捷键，所有操作触发配置保存
- 保留顶栏 Add/Remove 全局按钮不变

internal/ui/dialog_confirm_delete.go

@@ -0,0 +1,48 @@
+package ui
+
+import (
+	"fmt"
+
+	"gioui.org/layout"
+	"gioui.org/widget"
+	"gioui.org/widget/material"
+
+	"git.wxccs.org/iceking2nd/winauth-go/internal/i18n"
+)
+
+// confirmDeleteDialog asks the user to confirm deletion of a specific
+// entry. The dialog displays the target name verbatim in the prompt so
+// the user can sanity-check what they are about to lose.
+type confirmDeleteDialog struct {
+	name      string
+	okBtn     widget.Clickable
+	cancelBtn widget.Clickable
+}
+
+func newConfirmDeleteDialog(name string) *confirmDeleteDialog {
+	return &confirmDeleteDialog{name: name}
+}
+
+func (d *confirmDeleteDialog) Layout(
+	gtx layout.Context, th *material.Theme,
+	onDone func(confirmed bool),
+) layout.Dimensions {
+	if d.cancelBtn.Clicked(gtx) {
+		onDone(false)
+		return layout.Dimensions{Size: gtx.Constraints.Max}
+	}
+	if d.okBtn.Clicked(gtx) {
+		onDone(true)
+		return layout.Dimensions{Size: gtx.Constraints.Max}
+	}
+
+	body := func(gtx layout.Context) layout.Dimensions {
+		return layout.Flex{Axis: layout.Vertical}.Layout(gtx,
+			layout.Rigid(material.Body1(th,
+				fmt.Sprintf(i18n.T("msg_confirm_delete"), d.name)).Layout),
+		)
+	}
+	return modalCard(gtx, th, i18n.T("dialog_confirm_delete_title"),
+		i18n.T("btn_delete"), i18n.T("btn_cancel"),
+		&d.okBtn, &d.cancelBtn, body)
+}