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/helpers/hosted-download-failures.ts

@@ -0,0 +1,53 @@
+import type { LoadingBar } from './state.ts'
+
+export function createHostedDownloadFailures() {
+	const failures = new Map<string, LoadingBar>()
+	const retired = new Set<string>()
+	const currentTasks = new Map<string, string>()
+	return {
+		values: () => [...failures.values()],
+		has: (instanceId: string) => failures.has(instanceId),
+		isRetired: (id: string) => retired.has(id),
+		begin(instanceId: string, bars: LoadingBar[]) {
+			const current = currentTasks.get(instanceId)
+			if (current) retired.add(current)
+			currentTasks.delete(instanceId)
+			const previous = failures.get(instanceId)
+			if (previous) retired.add(String(previous.loading_bar_uuid))
+			for (const bar of bars) {
+				if (bar.bar_type?.type === 'hosted_pack_sync' && bar.bar_type.instance_id === instanceId) {
+					retired.add(String(bar.loading_bar_uuid))
+				}
+			}
+			failures.delete(instanceId)
+		},
+		update(payload: {
+			fraction: number | null
+			loader_uuid: string
+			event: LoadingBar['bar_type']
+		}) {
+			const event = payload.event
+			if (
+				event?.type !== 'hosted_pack_sync' ||
+				!event.instance_id ||
+				retired.has(payload.loader_uuid)
+			)
+				return
+			const current = currentTasks.get(event.instance_id)
+			if (current && current !== payload.loader_uuid) retired.add(current)
+			currentTasks.set(event.instance_id, payload.loader_uuid)
+			if (payload.fraction === null && event.error) {
+				failures.set(event.instance_id, {
+					loading_bar_uuid: payload.loader_uuid,
+					bar_type: event,
+					title: event.instance_name,
+					message: event.error,
+					total: 0,
+					current: 0,
+				})
+			} else {
+				failures.delete(event.instance_id)
+			}
+		},
+	}
+}