fix: mail skip semantics + PersonalMail wallet alignment

[TaprootFreak]

Summary

Fixes from #3654 (RealUnit Mail PR #3598 follow-ups):

• F2: Skipped RealUnit mails no longer falsely set recipientMail — new skipMail() / skipPendingMail() / skipChargebackMail() entity methods only write the date field to prevent re-processing, without implying a mail was sent. Fixes data integrity issue in audit/monitoring.
• F10: createPersonalMail now respects forcedLang from wallet config and passes walletName through the translation chain, consistent with createUserV2Mail.
• F6: createPersonalMail now calls getWalletBodyTexts() so wallet-specific body overrides apply.

Changed files

File	Change
buy-crypto.entity.ts	Add skipMail()
buy-fiat.entity.ts	Add skipPendingMail(), skipChargebackMail()
limit-request.entity.ts	Add skipMail()
buy-crypto-notification.service.ts	Use skip methods in 3 RealUnit guard paths
buy-fiat-notification.service.ts	Use skip methods in 3 RealUnit guard paths
limit-request-notification.service.ts	Use skip method in RealUnit guard path
mail.factory.ts	Align createPersonalMail with createUserV2Mail

Test plan

• Verify RealUnit pending/chargeback flows still advance state machine (mailSendDate set, record not re-picked)
• Verify recipientMail stays NULL for skipped RealUnit mails
• Verify non-RealUnit mail flows are unchanged (still call confirmSentMail etc.)
• If a PersonalMail is triggered for a wallet with forcedLang, verify correct language is used

Closes #3654 (F2, F6, F10)

[github-actions]

⚠️ Unverified Commits (1)

The following commits are not signed/verified:

• 5249949 style: fix prettier formatting in mail.factory.ts (Taproot Freak)

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