[Quotes]: Redirect to the invoice edit page after converting a quote

[nielsdrost7]

After QuoteService::convertQuoteToInvoice() runs (Modules/Quotes/Services/QuoteService.php, introduced in PR #579), the convert_to_invoice table action in Modules/Quotes/Filament/Company/Resources/Quotes/Tables/QuotesTable.php shows a success notification but does not navigate the user to the new draft invoice, because the EditInvoice Filament page did not exist on develop at the time. The EditInvoice page now exists on develop (further extended by PR #575 / issue #542), so this follow-up is unblocked.

Introduced as a deliberate deviation in PR #579 (feature/160-convert-quote-to-invoice).

Acceptance criteria

• Converting a quote redirects (or offers a one-click link in the success notification) to EditInvoice for the resulting draft invoice.
• Covered by a feature test asserting the redirect route + invoice id.