updated layout for webmail and added http dns letsencrypt

internal/db/mailbox_models.go

@@ -25,6 +25,9 @@ type Mailbox struct {
 	// MFAExempt overrides [Auth] enforce_mailbox_mfa off for this mailbox specifically,
 	// even if its domain isn't exempt.
 	MFAExempt bool
+	// GroupMessages collapses a run of same-subject messages in a folder view into one
+	// expandable row when true. Off by default — a display preference, not a policy.
+	GroupMessages bool
 }
 
 // MailboxSession is a self-service webmail portal login — a parallel schema to
@@ -143,6 +146,7 @@ type MailboxMessage struct {
 	CachedFrom      string
 	CachedTo        string
 	CachedSubject   string
+	CachedPreview   string
 	StoragePath     string
 	Nonce           []byte
 	CreatedAt       time.Time