Lets an invoice carry an additional Cc recipient alongside the primary
SendToEmail, sent via the ProcessWeb mailer API. Honors the
Fuchs:Email:OverrideRecipient dev safety net: when the override is
active, Cc is dropped entirely (only the single override inbox is
ever reached), never leaked to it.
- IComService.SendEmailAsync / ProcessWebComService: new optional
`cc` parameter, included in the mailer payload only when non-empty.
- FdsInvoiceData.RawInvoiceEmailCc + BuildInvoiceParams: reads
`new.invoiceemailcc`, posts @SendToEmailCc.
- IntranetController.Requests: reads SendToEmailCc from the loaded
invoice row and passes it through on send/resend.
- Fuchs_Database: SendToEmailCc column on fds__invoices, threaded
through fds__createInvoice/fds__setInvoice/fds__getInvoice and the
fds__tt__invoice_base/_core table types.
- fis.req_txt_de.js: "Zusatzempfänger (CC)" field label.
- Tests: ProcessWebComServiceTests (Cc included/omitted/dropped under
override); SystemStatusServiceTests mocks updated for the new
IComService.SendEmailAsync parameter.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>