fix(channelserver): post-RC1 stabilization sprint

Fix rasta_id=0 overwriting NULL in SaveMercenary, which prevented
game state saving for characters without a mercenary (#163).

Also includes:
- CHANGELOG updated with all 10 post-RC1 commits
- Setup wizard fmt.Printf replaced with zap structured logging
- technical-debt.md updated with 6 newly completed items
- Scenario binary format documented (docs/scenario-format.md)
- Tests: alliance nil-guard (#171), handler dispatch table,
  migrations (sorted/SQL/baseline), setup wizard (10 tests),
  protbot protocol sign/entrance/channel (23 tests)

server/channelserver/handlers_guild_alliance_test.go

@@ -505,3 +505,49 @@ func TestOperateJoint_NilAlliance(t *testing.T) {
 		t.Error("No response packet queued — would softlock the client")
 	}
 }
+
+// --- scanAllianceWithGuilds nil guild tests (issue #171) ---
+
+func TestInfoJoint_MissingSubGuild1(t *testing.T) {
+	// Verify that GetAllianceByID returns an error when sub guild 1 references
+	// a non-existent guild (nil return from GetByID). This is the scenario from
+	// issue #171 — a deleted guild causes a nil dereference in scanAllianceWithGuilds.
+	server := createMockServer()
+	guildMock := &mockGuildRepo{
+		// GetAllianceByID returns an error for missing guilds because
+		// scanAllianceWithGuilds calls GetByID for each sub guild.
+		// With guild=nil and SubGuild1ID > 0, GetByID returns nil,
+		// and scanAllianceWithGuilds should return an error rather than panic.
+		getAllianceErr: errNotFound,
+	}
+	server.guildRepo = guildMock
+	session := createMockSession(1, server)
+
+	pkt := &mhfpacket.MsgMhfInfoJoint{AckHandle: 100, AllianceID: 5}
+	handleMsgMhfInfoJoint(session, pkt)
+
+	// Handler should send a response even on error (not softlock)
+	select {
+	case <-session.sendPackets:
+	default:
+		t.Error("No response packet queued — would softlock the client")
+	}
+}
+
+func TestInfoJoint_MissingSubGuild2(t *testing.T) {
+	server := createMockServer()
+	guildMock := &mockGuildRepo{
+		getAllianceErr: errNotFound,
+	}
+	server.guildRepo = guildMock
+	session := createMockSession(1, server)
+
+	pkt := &mhfpacket.MsgMhfInfoJoint{AckHandle: 100, AllianceID: 6}
+	handleMsgMhfInfoJoint(session, pkt)
+
+	select {
+	case <-session.sendPackets:
+	default:
+		t.Error("No response packet queued — would softlock the client")
+	}
+}

server/channelserver/handlers_mercenary.go

@@ -194,7 +194,12 @@ func handleMsgMhfSaveMercenary(s *Session, p mhfpacket.MHFPacket) {
 	dumpSaveData(s, pkt.MercData, "mercenary")
 	if len(pkt.MercData) >= 4 {
 		temp := byteframe.NewByteFrameFromBytes(pkt.MercData)
-		if err := s.server.charRepo.SaveMercenary(s.charID, pkt.MercData, temp.ReadUint32()); err != nil {
+		rastaID := temp.ReadUint32()
+		if rastaID == 0 {
+			s.logger.Warn("Mercenary save with rasta_id=0, preserving existing value",
+				zap.Uint32("charID", s.charID))
+		}
+		if err := s.server.charRepo.SaveMercenary(s.charID, pkt.MercData, rastaID); err != nil {
 			s.logger.Error("Failed to save mercenary data", zap.Error(err))
 		}
 	}

server/channelserver/handlers_table_test.go

@@ -0,0 +1,59 @@
+package channelserver
+
+import (
+	"testing"
+
+	"erupe-ce/network"
+)
+
+func TestBuildHandlerTable_EntryCount(t *testing.T) {
+	table := buildHandlerTable()
+	// handlers_table.go has exactly 432 entries (one per packet ID).
+	// This test catches accidental deletions or duplicates.
+	const expectedCount = 432
+	if len(table) != expectedCount {
+		t.Errorf("handler table has %d entries, want %d", len(table), expectedCount)
+	}
+}
+
+func TestBuildHandlerTable_CriticalOpcodes(t *testing.T) {
+	table := buildHandlerTable()
+
+	critical := []struct {
+		name string
+		id   network.PacketID
+	}{
+		{"MSG_SYS_LOGIN", network.MSG_SYS_LOGIN},
+		{"MSG_SYS_LOGOUT", network.MSG_SYS_LOGOUT},
+		{"MSG_SYS_PING", network.MSG_SYS_PING},
+		{"MSG_SYS_ACK", network.MSG_SYS_ACK},
+		{"MSG_SYS_CAST_BINARY", network.MSG_SYS_CAST_BINARY},
+		{"MSG_SYS_ENTER_STAGE", network.MSG_SYS_ENTER_STAGE},
+		{"MSG_SYS_LEAVE_STAGE", network.MSG_SYS_LEAVE_STAGE},
+		{"MSG_MHF_SAVEDATA", network.MSG_MHF_SAVEDATA},
+		{"MSG_MHF_LOADDATA", network.MSG_MHF_LOADDATA},
+		{"MSG_MHF_ENUMERATE_QUEST", network.MSG_MHF_ENUMERATE_QUEST},
+		{"MSG_MHF_CREATE_GUILD", network.MSG_MHF_CREATE_GUILD},
+		{"MSG_MHF_INFO_GUILD", network.MSG_MHF_INFO_GUILD},
+		{"MSG_MHF_GET_ACHIEVEMENT", network.MSG_MHF_GET_ACHIEVEMENT},
+		{"MSG_MHF_PLAY_NORMAL_GACHA", network.MSG_MHF_PLAY_NORMAL_GACHA},
+		{"MSG_MHF_SEND_MAIL", network.MSG_MHF_SEND_MAIL},
+		{"MSG_MHF_SAVE_RENGOKU_DATA", network.MSG_MHF_SAVE_RENGOKU_DATA},
+		{"MSG_MHF_LOAD_RENGOKU_DATA", network.MSG_MHF_LOAD_RENGOKU_DATA},
+	}
+
+	for _, tc := range critical {
+		if _, ok := table[tc.id]; !ok {
+			t.Errorf("critical opcode %s (0x%04X) is not mapped in handler table", tc.name, uint16(tc.id))
+		}
+	}
+}
+
+func TestBuildHandlerTable_NoNilHandlers(t *testing.T) {
+	table := buildHandlerTable()
+	for id, handler := range table {
+		if handler == nil {
+			t.Errorf("handler for opcode 0x%04X is nil", uint16(id))
+		}
+	}
+}

server/channelserver/repo_character.go

@@ -193,8 +193,15 @@ func (r *CharacterRepository) ReadGuildPostChecked(charID uint32) (time.Time, er
 	return t, err
 }
 
-// SaveMercenary updates savemercenary and rasta_id atomically.
+// SaveMercenary updates savemercenary and optionally rasta_id.
+// When rastaID is 0, only the mercenary blob is saved — the existing rasta_id
+// (typically NULL for characters without a mercenary) is preserved. Writing 0
+// would pollute GetMercenaryLoans queries that match on pact_id.
 func (r *CharacterRepository) SaveMercenary(charID uint32, data []byte, rastaID uint32) error {
+	if rastaID == 0 {
+		_, err := r.db.Exec("UPDATE characters SET savemercenary=$1 WHERE id=$2", data, charID)
+		return err
+	}
 	_, err := r.db.Exec("UPDATE characters SET savemercenary=$1, rasta_id=$2 WHERE id=$3", data, rastaID, charID)
 	return err
 }