Surface charged-back payments as admin navbar notifications

[acirtautas]

Problem

A chargeback deliberately never transitions the Sylius payment (the dispute is handled in the EveryPay merchant portal), but the only trace was a warning log entry from the synchronizer - invisible to shop staff. A charged-back order could go unnoticed until the accounting did not add up.

Change

• New ChargedBackPaymentNotificationProvider (Sylius admin notification pipeline, tag sylius_admin.notification): every payment whose stored EveryPay state is charged_back appears in the admin navbar bell, newest first, capped at 10. The notification carries the order number and - for live payments - a link to the merchant portal (the configured white-label address, or the standard EveryPay portal). It stays visible until the dispute resolution callback updates the stored state.
• The message is translated in the provider, so it renders complete under any notifications template.
• The sylius_admin:navbar:notifications component template is swapped (via the existing twig-hooks file) for one with identical stock markup plus an optional link per notification; message-only notifications from other providers render exactly as before. If another plugin swaps the template again, only the link degrades away.
• Wiring mirrors the shop-bundle seam: src/Notification/ is excluded from the service prototype and config/services/integrations/sylius_admin.php loads only when SyliusAdminBundle is registered - shopless/adminless containers keep compiling.
• Portal-address resolution is extracted to EveryPayGateway::merchantPortalUrlFrom() (unit-tested); the state mapping and synchronizer are untouched.

Tests

• 5 functional tests on the admin dashboard: live chargeback with default portal link, configured white-label address wins, demo payment gets the message without a link, no notification without chargebacks, a charged-back payment of another gateway is ignored.
• Unit coverage for merchantPortalUrlFrom().

Translations

All four locales updated (en, lt, et, lv). Estonian and Latvian are machine-assisted: the chargeback phrasing ("makse vaidlustati" / "maksājums tika apstrīdēts") deserves a native check - the intent is "the payment was disputed/charged back".

Gates

phpunit (both suites), phpstan level 9, ecs, behat --strict - all green, also under composer update --prefer-lowest --prefer-stable.