feat: complete hosted mod sync and launcher interface updates

Add pack sync markers, tagged mod updates, parallel progress, JWT downloads and retry recovery. Include pending onboarding, about scene, compatibility data pack and download fixes.

apps/app-frontend/src/components/instance/HostedPackProgress.vue

@@ -0,0 +1,49 @@
+<script setup lang="ts">
+import { ProgressBar, defineMessages, useVIntl } from '@modrinth/ui'
+import { computed } from 'vue'
+import { injectDownloadManager } from '@/providers/download-manager'
+
+const props = defineProps<{ instanceId?: string; active?: boolean }>()
+const manager = injectDownloadManager()
+const { formatMessage } = useVIntl()
+const messages = defineMessages({
+	preparing: {
+		id: 'app.hosted-packs.progress.preparing',
+		defaultMessage: 'Preparing modpack installation…',
+	},
+	downloads: { id: 'app.hosted-packs.progress.downloads', defaultMessage: 'View downloads' },
+})
+const bar = computed(() =>
+	manager.legacyDownloads.value.find(
+		(item) =>
+			props.instanceId &&
+			item.bar_type?.type === 'hosted_pack_sync' &&
+			!item.bar_type.error &&
+			item.bar_type.instance_id === props.instanceId,
+	),
+)
+const waiting = computed(() => !bar.value?.total)
+const current = computed(() =>
+	Math.max(0, Math.min(bar.value?.current ?? 0, bar.value?.total ?? 0)),
+)
+const message = computed(() => bar.value?.message || formatMessage(messages.preparing))
+</script>
+
+<template>
+	<div v-if="active || bar" class="flex min-w-0 flex-col gap-2" role="status">
+		<ProgressBar
+			:progress="current"
+			:max="bar?.total || 1"
+			:waiting="waiting"
+			:label="message"
+			label-class="min-w-0 break-all text-sm text-secondary"
+			:show-progress="!waiting"
+			full-width
+		>
+			<template #progress-icon />
+		</ProgressBar>
+		<RouterLink to="/downloads" class="self-start text-sm text-brand hover:underline">
+			{{ formatMessage(messages.downloads) }}
+		</RouterLink>
+	</div>
+</template>