fix(tgbot): clear legacy panelProxy/tgBotProxy settings on upgrade

v3.3.1 removed the Panel Proxy URL field from the UI but left the stored
panelProxy/tgBotProxy values in the DB. The Telegram bot still reads
tgBotProxy directly, so a stale value masked the panelOutbound egress
fallback. Add a one-off seeder to drop both rows.

Closes #5266

internal/database/db.go

@@ -200,7 +200,7 @@ func runSeeders(isUsersEmpty bool) error {
 	}
 
 	if empty && isUsersEmpty {
-		seeders := []string{"UserPasswordHash", "ClientsTable", "InboundClientsArrayFix", "InboundClientTgIdFix", "InboundClientSubIdFix", "FreedomFinalRulesReverseFix", "ApiTokensHash"}
+		seeders := []string{"UserPasswordHash", "ClientsTable", "InboundClientsArrayFix", "InboundClientTgIdFix", "InboundClientSubIdFix", "FreedomFinalRulesReverseFix", "ApiTokensHash", "LegacyProxySettingsCleanup"}
 		for _, name := range seeders {
 			if err := db.Create(&model.HistoryOfSeeders{SeederName: name}).Error; err != nil {
 				return err
@@ -286,9 +286,27 @@ func runSeeders(isUsersEmpty bool) error {
 			return err
 		}
 	}
+
+	if !slices.Contains(seedersHistory, "LegacyProxySettingsCleanup") {
+		if err := clearLegacyProxySettings(); err != nil {
+			return err
+		}
+	}
 	return nil
 }
 
+// clearLegacyProxySettings drops the deprecated panelProxy/tgBotProxy rows so a
+// stale tgBotProxy no longer masks the panelOutbound egress fallback.
+func clearLegacyProxySettings() error {
+	return db.Transaction(func(tx *gorm.DB) error {
+		if err := tx.Where("key IN ?", []string{"panelProxy", "tgBotProxy"}).
+			Delete(&model.Setting{}).Error; err != nil {
+			return err
+		}
+		return tx.Create(&model.HistoryOfSeeders{SeederName: "LegacyProxySettingsCleanup"}).Error
+	})
+}
+
 func normalizeInboundClientTgId() error {
 	var inbounds []model.Inbound
 	if err := db.Find(&inbounds).Error; err != nil {