feat(tenancy): add resend invitation for pending team members

New resend_invitation() service method regenerates the token and
resends the invitation email for pending members.

Available on all frontends:
- Merchant: POST /merchants/account/team/stores/{sid}/members/{uid}/resend
- Store: POST /store/team/members/{uid}/resend

UI: paper-airplane icon appears on pending members in both merchant
and store team pages.

i18n: resend_invitation + invitation_resent keys in 4 locales.
Also translated previously untranslated invitation_sent_successfully
in fr/de/lb.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/tenancy/locales/de.json

@@ -51,6 +51,7 @@
         "title": "Team",
         "total_members": "Mitglieder gesamt",
         "personal_info": "Persönliche Informationen",
+        "resend_invitation": "Einladung erneut senden",
         "save_profile": "Profil speichern",
         "view_member": "Mitglied anzeigen",
         "account_information": "Kontoinformationen",
@@ -75,7 +76,8 @@
         "please_fix_the_errors_before_saving": "Please fix the errors before saving",
         "profile_updated_successfully": "Profile updated successfully",
         "email_is_required": "Email is required",
-        "invitation_sent_successfully": "Invitation sent successfully",
+        "invitation_sent_successfully": "Einladung erfolgreich gesendet",
+        "invitation_resent": "Einladung erneut gesendet",
         "team_member_updated": "Team member updated",
         "team_member_removed": "Team member removed",
         "invalid_merchant_url": "Invalid merchant URL",