Adds useSheetScopeEntityId hook used by both AttachProductSheet and
CreateScheduleSheet, which seeds scope from ?entity_id= and falls back
to the customer's active entity-level plan when no customer-level plan
exists. AttachFormProvider now exposes entityId and onScopeChange on
context, so AttachProductSelection and the scope dropdown pull from
the form context instead of the page-level useEntity() store.
Made-with: Cursor
Remove the payment-method requirement from create_schedule. When no payment
method exists the flow now generates a Stripe Checkout URL (matching attach).
Add invoice_mode and redirect_mode params to the schedule API, wire up a
review → send-invoice sheet flow in the dashboard, and expose
redirect_to_checkout on the schedule preview response.
Made-with: Cursor
