fix(channelserver): return error from Save() to prevent misleading success logs

CharacterSaveData.Save() silently returned on failure (nil decompressed
data, compression error, DB error) while the caller unconditionally
logged "Saved character data successfully". This made diagnosing save
failures difficult (ref #163).

Save() now returns an error, and all six call sites check it. The
success log in saveAllCharacterData only fires when the save actually
persisted.

server/channelserver/handlers_character.go

@@ -3,6 +3,7 @@ package channelserver
 import (
 	"database/sql"
 	"errors"
+	"fmt"
 
 	cfg "erupe-ce/config"
 	"erupe-ce/network/mhfpacket"
@@ -46,12 +47,12 @@ func GetCharacterSaveData(s *Session, charID uint32) (*CharacterSaveData, error)
 	return saveData, nil
 }
 
-func (save *CharacterSaveData) Save(s *Session) {
+func (save *CharacterSaveData) Save(s *Session) error {
 	if save.decompSave == nil {
 		s.logger.Warn("No decompressed save data, skipping save",
 			zap.Uint32("charID", save.CharID),
 		)
-		return
+		return errors.New("no decompressed save data")
 	}
 
 	if !s.kqfOverride {
@@ -66,7 +67,7 @@ func (save *CharacterSaveData) Save(s *Session) {
 		err := save.Compress()
 		if err != nil {
 			s.logger.Error("Failed to compress savedata", zap.Error(err))
-			return
+			return fmt.Errorf("compress savedata: %w", err)
 		}
 	} else {
 		// Saves were not compressed
@@ -75,11 +76,15 @@ func (save *CharacterSaveData) Save(s *Session) {
 
 	if err := s.server.charRepo.SaveCharacterData(save.CharID, save.compSave, save.HR, save.GR, save.Gender, save.WeaponType, save.WeaponID); err != nil {
 		s.logger.Error("Failed to update savedata", zap.Error(err), zap.Uint32("charID", save.CharID))
+		return fmt.Errorf("save character data: %w", err)
 	}
 
 	if err := s.server.charRepo.SaveHouseData(s.charID, save.HouseTier, save.HouseData, save.BookshelfData, save.GalleryData, save.ToreData, save.GardenData); err != nil {
 		s.logger.Error("Failed to update user binary house data", zap.Error(err))
+		return fmt.Errorf("save house data: %w", err)
 	}
+
+	return nil
 }
 
 func handleMsgMhfSexChanger(s *Session, p mhfpacket.MHFPacket) {

server/channelserver/handlers_character_test.go

@@ -476,7 +476,9 @@ func TestCharacterSaveData_Save_Integration(t *testing.T) {
 	saveData.WeaponID = 1234
 
 	// Save it
-	saveData.Save(s)
+	if err := saveData.Save(s); err != nil {
+		t.Fatalf("Save failed: %v", err)
+	}
 
 	// Reload and verify
 	var hr, gr uint16

server/channelserver/handlers_data.go

@@ -91,7 +91,10 @@ func handleMsgMhfSavedata(s *Session, p mhfpacket.MHFPacket) {
 	}
 
 	if characterSaveData.Name == s.Name || s.server.erupeConfig.RealClientMode <= cfg.S10 {
-		characterSaveData.Save(s)
+		if err := characterSaveData.Save(s); err != nil {
+			s.logger.Error("Failed to save character data", zap.Error(err))
+			return
+		}
 		s.logger.Info("Wrote recompressed savedata back to DB.")
 	} else {
 		_ = s.rawConn.Close()

server/channelserver/handlers_distitem.go

@@ -156,7 +156,9 @@ func handleMsgMhfAcquireDistItem(s *Session, p mhfpacket.MHFPacket) {
 					saveData, err := GetCharacterSaveData(s, s.charID)
 					if err == nil {
 						saveData.RP += uint16(item.Quantity)
-						saveData.Save(s)
+						if err := saveData.Save(s); err != nil {
+							s.logger.Error("Failed to save RP from dist item", zap.Error(err))
+						}
 					}
 				}
 			}

server/channelserver/handlers_guild_ops.go

@@ -183,7 +183,9 @@ func handleDonateRP(s *Session, amount uint16, guild *Guild, _type int) []byte {
 		}
 	}
 	saveData.RP -= amount
-	saveData.Save(s)
+	if err := saveData.Save(s); err != nil {
+		s.logger.Error("Failed to save RP after guild donation", zap.Error(err))
+	}
 	switch _type {
 	case 0:
 		if err := s.server.guildRepo.AddRankRP(guild.ID, amount); err != nil {

server/channelserver/handlers_session.go

@@ -194,7 +194,14 @@ func saveAllCharacterData(s *Session, rpToAdd int) error {
 	}
 
 	// Save to database (main savedata + user_binary)
-	characterSaveData.Save(s)
+	if err := characterSaveData.Save(s); err != nil {
+		s.logger.Error("Failed to save character data",
+			zap.Error(err),
+			zap.Uint32("charID", s.charID),
+			zap.String("name", s.Name),
+		)
+		return err
+	}
 
 	// Save auxiliary data types
 	// Note: Plate data saves immediately when client sends save packets,

server/channelserver/handlers_tower.go

@@ -376,7 +376,9 @@ func handleMsgMhfPostTenrouirai(s *Session, p mhfpacket.MHFPacket) {
 		sd, err := GetCharacterSaveData(s, s.charID)
 		if err == nil && sd != nil {
 			sd.RP -= pkt.DonatedRP
-			sd.Save(s)
+			if err := sd.Save(s); err != nil {
+				s.logger.Error("Failed to save RP after tower donation", zap.Error(err))
+			}
 			result, err := s.server.towerService.DonateGuildTowerRP(pkt.GuildID, pkt.DonatedRP)
 			if err != nil {
 				s.logger.Error("Failed to process tower RP donation", zap.Error(err))