test: add coverage tests to reach 65% total coverage

Add 16 test files across 4 packages covering previously untested
handler paths: guild board operations, house/warehouse management,
tower/tenrouirai progress, diva schedule, festa info, cafe duration,
API error paths, sign server responses, and byteframe boundaries.

server/channelserver/handlers_cafe_extra_coverage_test.go

@@ -0,0 +1,52 @@
+package channelserver
+
+import (
+	cfg "erupe-ce/config"
+	"erupe-ce/network/mhfpacket"
+	"testing"
+	"time"
+)
+
+func TestHandleMsgMhfGetCafeDuration_ResetPath(t *testing.T) {
+	srv := createMockServer()
+	charRepo := newMockCharacterRepo()
+	// cafe_reset in the past to trigger reset logic
+	charRepo.times["cafe_reset"] = time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC)
+	charRepo.ints["cafe_time"] = 1800
+	srv.charRepo = charRepo
+	srv.cafeRepo = &mockCafeRepo{}
+	s := createMockSession(100, srv)
+
+	pkt := &mhfpacket.MsgMhfGetCafeDuration{AckHandle: 1}
+	handleMsgMhfGetCafeDuration(s, pkt)
+	<-s.sendPackets
+}
+
+func TestHandleMsgMhfGetCafeDuration_NoResetTime(t *testing.T) {
+	srv := createMockServer()
+	charRepo := newMockCharacterRepo()
+	// No cafe_reset set → ReadTime returns error → sets new reset time
+	charRepo.ints["cafe_time"] = 100
+	srv.charRepo = charRepo
+	srv.cafeRepo = &mockCafeRepo{}
+	s := createMockSession(100, srv)
+
+	pkt := &mhfpacket.MsgMhfGetCafeDuration{AckHandle: 1}
+	handleMsgMhfGetCafeDuration(s, pkt)
+	<-s.sendPackets
+}
+
+func TestHandleMsgMhfGetCafeDuration_ZZClient(t *testing.T) {
+	srv := createMockServer()
+	srv.erupeConfig.RealClientMode = cfg.ZZ
+	charRepo := newMockCharacterRepo()
+	charRepo.times["cafe_reset"] = time.Date(2099, 12, 31, 0, 0, 0, 0, time.UTC)
+	charRepo.ints["cafe_time"] = 3600
+	srv.charRepo = charRepo
+	srv.cafeRepo = &mockCafeRepo{}
+	s := createMockSession(100, srv)
+
+	pkt := &mhfpacket.MsgMhfGetCafeDuration{AckHandle: 1}
+	handleMsgMhfGetCafeDuration(s, pkt)
+	<-s.sendPackets
+}