feat(sub): allow identity tokens on every subscription link (#5935)

Keep usage tokens first-link-only while adding an opt-in setting for repeating EMAIL and USERNAME in subscription-body remarks.

Co-authored-by: x06579 <x06579@ai-dashboard>

internal/web/service/setting.go

@@ -66,6 +66,7 @@ var defaultValueMap = map[string]string{
 	"expireDiff":                  "0",
 	"trafficDiff":                 "0",
 	"remarkTemplate":              DefaultRemarkTemplate,
+	"subShowIdentityOnAllLinks":   "false",
 	"timeLocation":                "Local",
 	"tgBotEnable":                 "false",
 	"tgBotToken":                  "",
@@ -649,6 +650,10 @@ func (s *SettingService) GetRemarkTemplate() (string, error) {
 	return s.getString("remarkTemplate")
 }
 
+func (s *SettingService) GetSubShowIdentityOnAllLinks() (bool, error) {
+	return s.getBool("subShowIdentityOnAllLinks")
+}
+
 func (s *SettingService) GetSecret() ([]byte, error) {
 	secret, err := s.getString("secret")
 	if secret == defaultValueMap["secret"] {