[Invoices]: Create a recurring invoice from an existing invoice (edit action)

[nielsdrost7]

The EditInvoice header action bar (Modules/Invoices/Filament/Company/Resources/Invoices/Pages/EditInvoice.php) has a create_recurring action that currently only shows a "not yet implemented" warning toast. It should create a RecurringInvoice record (see Modules/Invoices/Models/RecurringInvoice.php) seeded from the current invoice's line items and customer, then let the user manage/confirm the recurrence schedule.

Introduced as a stub in PR #575 (feature/542-invoice-edit-page).

Part of the broader #52 Epic Recurring-Invoices.

Acceptance criteria

• create_recurring action on the invoice edit page opens a form to configure recurrence (frequency, start date, end condition) pre-filled from the source invoice.
• Submitting creates a RecurringInvoice linked to the source invoice's customer and item set.
• Action is hidden/disabled for invoices that already have an active recurring invoice, if applicable.
• Toast confirms creation and links to the new recurring invoice.