fix(core): build the force-account-model exempt scope lazily (PR #433)

Merges aaapl's fix for the dashboard failing to mount since v3.5.62.
693ea10d added a module-scope `new AsyncLocalStorage()` in force-account-model.ts,
which core/index.ts re-exports and dashboard-web imports transitively; Bun's
browser target has no node:async_hooks and stubs it to an empty object, so the
constructor call threw during chunk init and killed the React bootstrap.