[PM-40167] feat: Update billing domain email copy

[cyprain-okeke]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-40167
https://bitwarden.atlassian.net/browse/PM-42261
https://bitwarden.atlassian.net/browse/PM-42262
https://bitwarden.atlassian.net/browse/PM-42264

📔 Objective

Refreshes subject lines and body copy for nine billing-domain emails (HTML + text variants) per the PM-38898 terminology epic:

• LicenseExpired — subject only ("License expired")
• OrganizationSeatsMaxReached / OrganizationSmSeatsMaxReached / OrganizationSmServiceAccountsMaxReached — lowercased subjects; body now leads with the organization name (added OrganizationName to the view models via CoreHelpers.SanitizeForEmail)
• Provider/ProviderUpdatePaymentMethod — "Your Bitwarden organization…" copy and Admin Console navigation wording
• FamiliesForEnterprise offer (new + existing account), sponsorship reverting, and removed-from-family emails — "Sponsored Families Plan" terminology, updated subjects and body copy

Additional changes riding along:

• Removed the now-unused offerAcceptanceDate parameter from SendFamiliesForEnterpriseRemoveSponsorshipsEmailAsync (interface, both implementations, caller, tests)
• Sponsor org name in offer emails now passes through CoreHelpers.SanitizeForEmail, matching the sibling sponsorship-removal email
• Fixed the sponsorship-reverting text template referencing a nonexistent {{Date}} property (previously rendered a blank date); both variants now use {{date ExpirationDate 'MMMM dd, yyyy'}}
• Unit tests added for all changed emails, rendering the real embedded templates and asserting subjects, body copy (HTML + text), retained CTA links/disclaimers, and date formatting

Notes for reviewers:

• The ticket description still says the copy is gated behind the vfo1-foundation flag as duplicate V2 templates — that's stale. Nick Krantz confirmed the copy ships in-place with no flag; the ticket AC predates that decision.
• The removed-sponsorship email keeps the "Or click the following link: {subscription URL}" line per the ticket's copy spec. In the HTML variant this renders the raw URL as visible link text (previously anchored behind "Subscription page") and the "Or" no longer has an antecedent — flagged to product as a copy-deck question rather than deviating from the specified copy here.

[github-actions]

ℹ️ Limited Platform familiarity

This PR touches a platform-community area. The Platform team owns this code but does not actively develop it, so a Platform review here may be less authoritative than usual.

[github-actions]

🤖 Bitwarden Claude Code Review

Overall Assessment: APPROVE

Re-reviewed after the [PM-42261] fix: Address QA defects on billing domain emails commit, on top of the previously reviewed copy updates across nine billing-domain email templates (HTML + text), the OrganizationName view model additions, the subject line changes in HandlebarsMailService, and the removal of the offerAcceptanceDate parameter from SendFamiliesForEnterpriseRemoveSponsorshipsEmailAsync. Verified the four QA fixes: dropping CoreHelpers.SanitizeForEmail from the seat/machine-account and sponsorship-offer names is safe because all three sites render through escaping double-stashes and the recipients are the organization's own owners (the sponsorship-offer call site is unchanged relative to main); switching the offer text templates and ProviderUpdatePaymentMethod.text.hbs to triple-stash removes HTML-encoded ampersands and a stray <a> tag from plain-text bodies, while the HTML template correctly retains the link helper; and OrganizationServiceAccountsMaxReachedViewModel now inheriting BaseMailModel supplies the CurrentYear the FullHtmlLayout footer needs (neither WebVaultUrl nor SiteName is referenced by that layout). Also confirmed {{date ExpirationDate 'MMMM dd, yyyy'}} matches the registered helper signature and existing template usage, all three OrganizationSeatsMaxReached*/ServiceAccounts* construction sites populate OrganizationName, the interface change is propagated to both IMailService implementations and the sole caller, and no stale references to OfferAcceptanceDate, {{Date}}, or the old subject strings remain in src/, test/, or bitwarden_license/.

Code Review Details

No findings at or above the reporting threshold.

Notes considered and intentionally not raised as findings:

• The dangling "Or click the following link:" line in FamiliesForEnterpriseRemovedFromFamilyUser (both variants) is already documented in the PR description as an open copy-deck question with product.
• {{OrganizationName}} in the .text.hbs variants is HTML-escaped by Handlebars, so an org name containing & renders as & in the plain-text body. This matches the existing convention across ~15 other text templates (AdminResetPassword, LicenseExpired, OrganizationUserAccepted, etc.) and is not introduced by this PR.
• The /billing/payment-method → /billing/payment-details route change and the help-article anchor change cannot be verified from this repository; both are explicitly part of the QA-defect fix (PM-42262) and are assumed validated against the web client.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.40%. Comparing base (ac309aa) to head (9782ff5).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8203      +/-   ##
==========================================
+ Coverage   63.29%   63.40%   +0.10%     
==========================================
  Files        2401     2401              
  Lines      104043   104045       +2     
  Branches     9426     9426              
==========================================
+ Hits        65857    65971     +114     
+ Misses      35930    35815     -115     
- Partials     2256     2259       +3     

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[djsmith85]

Approving for platform