feat: 跨实例同步移植第8轮（前端 helpers + 同步设置 UI）

新增同步 helpers（synced-options / synced-packs / game-options），在 instance helper 中补充同步类型与 API。新增实例设置「同步」标签页（SyncSettings）及 SyncSource / SyncedPacks / servers / command-history 四个弹窗，并把 CheckCircleButton、TeleportOverflowMenu 从 ui 包导出。同步相关的 en-US / zh-CN 文案已补齐（各 62 条）。game-settings-modal 留待下一轮。

apps/app-frontend/src/helpers/synced-packs.ts

@@ -0,0 +1,83 @@
+import type { ContentItem } from '@modrinth/ui'
+import { queryOptions } from '@tanstack/vue-query'
+import { invoke } from '@tauri-apps/api/core'
+
+import { adaptContentItems, isSyncedOptionAvailable } from './instance'
+
+export type SyncedPackType = 'resourcepack' | 'datapack'
+export type SyncedPackAction = 'enable' | 'disable'
+
+export type DesyncServerMode = 'keep_in_other_instances' | 'remove_from_other_instances'
+
+export function isSyncedPackTypeAvailable(projectType: ContentItem['project_type']): boolean {
+	return (
+		['resourcepack', 'datapack'].includes(projectType) &&
+		isSyncedOptionAvailable(projectType === 'resourcepack' ? 'resource_packs' : 'data_packs')
+	)
+}
+
+export interface PackSyncPreview {
+	pack: ContentItem
+	instances: {
+		instance_id: string
+		name: string
+		game_version: string
+		compatible: boolean
+		participating: boolean
+	}[]
+}
+
+export const syncedPackKeys = {
+	all: ['synced-packs'] as const,
+	list: (type: SyncedPackType) => ['synced-packs', 'list', type] as const,
+}
+
+export function syncedPackQueryOptions(type: SyncedPackType) {
+	return queryOptions({
+		queryKey: syncedPackKeys.list(type),
+		queryFn: () => list_synced_packs(type),
+		enabled: isSyncedPackTypeAvailable(type),
+	})
+}
+
+export async function list_synced_packs(projectType: SyncedPackType): Promise<ContentItem[]> {
+	const items = await invoke<ContentItem[]>('plugin:instance|instance_list_synced_packs', {
+		projectType,
+	})
+	return adaptContentItems(items).map((item) => ({ ...item, external: !item.project }))
+}
+
+export function get_pack_sync_preview(
+	instanceId: string,
+	projectPath: string,
+): Promise<PackSyncPreview> {
+	return invoke('plugin:instance|instance_get_pack_sync_preview', { instanceId, projectPath })
+}
+
+export function sync_pack(instanceId: string, projectPath: string): Promise<void> {
+	return invoke('plugin:instance|instance_sync_pack', { instanceId, projectPath })
+}
+
+export function desync_pack(
+	instanceId: string,
+	packId: string,
+	mode: DesyncServerMode,
+): Promise<void> {
+	return invoke('plugin:instance|instance_desync_pack', { instanceId, packId, mode })
+}
+
+export function upload_synced_pack(
+	path: string,
+	projectType: SyncedPackType,
+	gameVersions: string[],
+): Promise<void> {
+	return invoke('plugin:instance|instance_upload_synced_pack', { path, projectType, gameVersions })
+}
+
+export function set_synced_pack_enabled(packId: string, enabled: boolean): Promise<void> {
+	return invoke('plugin:instance|instance_set_synced_pack_enabled', { packId, enabled })
+}
+
+export function remove_synced_pack(packId: string): Promise<void> {
+	return invoke('plugin:instance|instance_remove_synced_pack', { packId })
+}