lint: remove unused code from platform/label_studio, email, dashboard, sync

- Delete sync/text.go, sync/tile.go, platform/dashboard.go (entirely unused)
- Remove unused vars/funcs from platform/label_studio.go (9 items)
- Remove contentEmailInitial, contentEmailReportConfirmation,
  newContentEmailNotificationConfirmation, contentEmailBase from platform/email

platform/email/initial.go

@@ -10,12 +10,6 @@ import (
 	//"github.com/rs/zerolog/log"
 )
 
-type contentEmailInitial struct {
-	Base         contentEmailBase
-	Destination  string
-	URLSubscribe string
-}
-
 func maybeSendInitialEmail(ctx context.Context, destination string) error {
 	err := EnsureInDB(ctx, destination)
 	if err != nil {

platform/email/report_notification_confirmation.go

@@ -8,11 +8,6 @@ import (
 	//"github.com/rs/zerolog/log"
 )
 
-type contentEmailReportConfirmation struct {
-	Base            contentEmailBase
-	URLReportStatus string
-}
-
 func SendReportConfirmation(ctx context.Context, destination, report_id string) error {
 	err := maybeSendInitialEmail(ctx, destination)
 	if err != nil {
@@ -31,7 +26,4 @@ func SendReportConfirmation(ctx context.Context, destination, report_id string)
 	return sendEmailBegin(ctx, config.ForwardEmailRMOAddress, destination, templateReportNotificationConfirmationID, subject, data)
 }
 
-func newContentEmailNotificationConfirmation(report_id string) (result contentEmailReportConfirmation) {
-	result.URLReportStatus = config.MakeURLReport("/status/%s", report_id)
-	return result
-}
+

platform/email/template.go

@@ -38,12 +38,6 @@ var (
 	templateReportNotificationConfirmationID int32
 )
 
-type contentEmailBase struct {
-	URLLogo          string
-	URLUnsubscribe   string
-	URLViewInBrowser string
-}
-
 type ContentEmailRender struct {
 	IsBrowser bool
 	C         any