Add support for AsyncLocalStorage (nodejs_als) on Oxygen

[RATIU5]

Feature request: add support AsyncLocalStorage (nodejs_als) on Oxygen

Versions: @shopify/mini-oxygen 4.2.2, @shopify/hydrogen 2026.10.0-preview.3, @shopify/cli 3.x

Context
Follow-up to #3828, where it was confirmed that ALS isn't available in Oxygen production. The Hydrogen developer preview now targets any framework, but several of them need AsyncLocalStorage for request scoping:

• Solid 2 start mode: @solidjs/web/storage imports node:async_hooks unconditionally, so the worker fails to start
• TanStack Start: @tanstack/start-storage-context and start-server-core import it
• Sentry: per the Sentry maintainer in Shopify hydrogen dev fails to load app entry with No such module "node:async_hooks" when using Sentry (@sentry/cloudflare) #3828, the v11 Cloudflare SDK will require nodejs_compat

Today these either can't deploy to Oxygen or need unofficial workarounds, like needing to alias framework internals.

Request
I think any of these would help, in order of my preference:

1. Enable the nodejs_als compatibility flag on Oxygen (ALS only, a small surface I presume)
2. Allow compatibility flags in oxygen.json alongside compatibility_date, with MiniOxygen reading the same config so dev and prod match (as suggested in Shopify hydrogen dev fails to load app entry with No such module "node:async_hooks" when using Sentry (@sentry/cloudflare) #3828)
3. If neither is planned, document this limitation on the Oxygen runtime page, which currently doesn't mention node:* built-ins or compatibility flags

Repro
A worker containing import { AsyncLocalStorage } from 'node:async_hooks', run with createMiniOxygen({ workers: [{ modules: true, scriptPath }] }), fails with Unable to resolve ... "node:async_hooks". It runs with compatibilityFlags: ['nodejs_als'].

Is ALS support on the roadmap? Happy to test a preview.

[RATIU5]

Update: ALS works on Oxygen when oxygen.json compatibility_date ≥ 2026-08-04 (verified on preview deploys: 2025-04-01 → No such module "node:async_hooks"; 2026-08-04 / 2026-09-01 → works). So this is less "add ALS" and more:

1. Expose the compatibility date as a supported option (the hydrogen() Vite plugin hard-codes 2025-04-01; oxygen() has no public option), and confirm dates ≥ 2026-08-04 are supported for production.
2. Update MiniOxygen's bundled workerd (currently 1.20250310.0) so local dev matches.
3. Document this on the Oxygen runtime page.