feat(affiliates): admin management and convert earnings to account balance

[hedon77]

Admin affiliate management (list, detail, edit) plus converting an affiliate's earnings into account balance.

[Panelica]

Nice consolidation, and thanks for updating all the route references and tests. One correctness note: convertToCredit() moves money in three steps (affiliate balance, withdrawn, client credit) plus a Transaction row without a surrounding DB::transaction(). A failure mid-way could desync the balances — please wrap it (and ideally lock the row) so it's atomic.

[hedon77]

Fixed — convertToCredit() now runs inside a DB::transaction() with lockForUpdate() on the affiliate row, so the balance/withdrawn/credit updates and the Transaction row are atomic.

[Panelica]

Thank you — and thanks for wrapping convertToCredit() in a DB::transaction() with lockForUpdate(), exactly right. We just merged the first clean batch into main: #16 (client delete), #24 (invoice number display), #13 (Tpay), #22 (addon settings framework) and #14 (tax rewrite). This currently conflicts with main because it overlaps the config controller and admin routes we touched. Could you rebase it on the updated main? Then it's good to go.

[hedon77]

*Zrebasowane na aktualny \main* — czyste, gotowe do merga.

Potwierdzam też poprawkę z Twojej uwagi: \convertToCredit()\ od początku tej wersji działa wewnątrz \DB::transaction()\ i blokuje wiersz przez \lockForUpdate()\ (\�pp/Services/AffiliateService.php:85-86), więc update'owanie salda affiliate + withdrawn + kredytu klienta + wpis \Transaction\ jest atomowe.

[Panelica]

Thank you — and thanks again for making convertToCredit() transactional. We merged #9, #20 and #21, which overlap this on the config, routes and invoice files, so it now conflicts with main. A quick rebase and it's ready to merge.

[hedon77]

*Zrebasowane na aktualny \main* (po zmergowaniu #9/#20/#21) — gałąź merguje się teraz czysto. Atomowość \convertToCredit()\ bez zmian (\DB::transaction()\ + \lockForUpdate()). Gotowe do merga.

[Panelica]

Thank you — we merged #19 (company lookup, now gated behind the addon) and #17 (billing email). This one now conflicts with main again on the shared admin views/config. One more rebase on the updated main and it is ready to merge. Appreciated, and sorry for the repeated rebases — the invoicing cluster overlaps a lot.