feat(ksef): KSeF status under Billing menu (addon-gated)

[hedon77]

Przenosi status wysylek do KSeF z ekranu addonu do dedykowanej strony Rozliczenia -> KSeF status (admin/ksef/index). Nowa trasa admin.ksef.index + widok admin/ksef/index.blade.php. KsefModule::output() zostaje jako odsylacz. Pozycja menu w dropdownie Rozliczenia oraz sidebarze, widoczna tylko gdy modul KSeF wlaczony (AddonManager::isActive). Tlumaczenia EN/PL.

[Panelica]

Merged — thank you, this is a well-judged reorganisation. Moving the KSeF submission list out of the addon page into a dedicated Billing → KSeF status screen (addon-gated via ksefActive on the composer) reads much better than the old inline table, and the connection-test button staying on the module page is the right split.

The SendNotificationListener change is the important one and it's correct: when KSeF is active and the invoice is VAT, skipping the plain InvoiceCreatedMail avoids a duplicate — the customer gets the definitive KsefInvoiceIssuedMail (numbered PDF + QR) instead, while proformas keep the normal email. That lines up exactly with the #26/#28 flow.

One thing I completed on merge (follow-up acf0292): the new addon_modules.changelog, nav.ksef_status and ksef.addon_moved_hint keys, plus the company_lookup retitle, landed in en+pl only — I added the Turkish and Simplified Chinese so the parity and Simplified-Chinese-mirror tests stay green. Full suite is green (2340 passing; only the two pre-existing environmental db-backup tests remain).