fix(tenancy): use absolute URL in team invitation email link

Email clients need absolute URLs to make links clickable. The
acceptance_link was a relative path (/store/invitation/accept?token=...)
which rendered as plain text. Now prepends the platform domain with
the correct protocol.

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

app/modules/tenancy/services/store_team_service.py

@@ -980,9 +980,13 @@ class StoreTeamService:
         role_name: str,
     ):
         """Send team invitation email."""
+        from app.core.config import settings as app_settings
         from app.modules.messaging.services.email_service import EmailService
 
-        acceptance_link = f"/store/invitation/accept?token={token}"
+        domain = app_settings.main_domain.rstrip("/")
+        scheme = "http" if "localhost" in domain else "https"
+        base_url = f"{scheme}://{domain}" if "://" not in domain else domain
+        acceptance_link = f"{base_url}/store/invitation/accept?token={token}"
 
         email_service = EmailService(db)
         email_service.send_template(