test: expand channelserver coverage from 12% to 16%

Add comprehensive tests for handler files:
- handlers_object: object creation, positioning, binary ops
- handlers_semaphore: create, acquire, release, check, delete
- handlers_reserve: stub handlers and reserve188/18B
- handlers_event: registration, release, feature weapons
- handlers_mutex: create, open, close, delete operations
- handlers_campaign: enumerate, state, apply
- handlers_bbs: user status, SNS status, article apply
- handlers_tournament: info, entry, acquire
- handlers_users: user binary operations
- handlers_clients: client enumeration
- handlers_rengoku: ranking
- handlers_register: raviente semaphore functions
- handlers_tower: tower info, tenrouirai, seibatu ranking

All tests pass with race detection enabled.

server/channelserver/handlers_reserve_test.go

@@ -0,0 +1,138 @@
+package channelserver
+
+import (
+	"testing"
+
+	"erupe-ce/network/mhfpacket"
+)
+
+// Test that reserve handlers with AckHandle respond correctly
+
+func TestHandleMsgSysReserve188(t *testing.T) {
+	server := createMockServer()
+	session := createMockSession(1, server)
+
+	pkt := &mhfpacket.MsgSysReserve188{
+		AckHandle: 12345,
+	}
+
+	handleMsgSysReserve188(session, pkt)
+
+	// Verify response packet was queued
+	select {
+	case p := <-session.sendPackets:
+		if len(p.data) == 0 {
+			t.Error("Response packet should have data")
+		}
+	default:
+		t.Error("No response packet queued")
+	}
+}
+
+func TestHandleMsgSysReserve18B(t *testing.T) {
+	server := createMockServer()
+	session := createMockSession(1, server)
+
+	pkt := &mhfpacket.MsgSysReserve18B{
+		AckHandle: 12345,
+	}
+
+	handleMsgSysReserve18B(session, pkt)
+
+	// Verify response packet was queued
+	select {
+	case p := <-session.sendPackets:
+		if len(p.data) == 0 {
+			t.Error("Response packet should have data")
+		}
+	default:
+		t.Error("No response packet queued")
+	}
+}
+
+// Test that empty reserve handlers don't panic
+
+func TestEmptyReserveHandlers(t *testing.T) {
+	server := createMockServer()
+	session := createMockSession(1, server)
+
+	tests := []struct {
+		name    string
+		handler func(s *Session, p mhfpacket.MHFPacket)
+	}{
+		{"handleMsgSysReserve55", handleMsgSysReserve55},
+		{"handleMsgSysReserve56", handleMsgSysReserve56},
+		{"handleMsgSysReserve57", handleMsgSysReserve57},
+		{"handleMsgSysReserve01", handleMsgSysReserve01},
+		{"handleMsgSysReserve02", handleMsgSysReserve02},
+		{"handleMsgSysReserve03", handleMsgSysReserve03},
+		{"handleMsgSysReserve04", handleMsgSysReserve04},
+		{"handleMsgSysReserve05", handleMsgSysReserve05},
+		{"handleMsgSysReserve06", handleMsgSysReserve06},
+		{"handleMsgSysReserve07", handleMsgSysReserve07},
+		{"handleMsgSysReserve0C", handleMsgSysReserve0C},
+		{"handleMsgSysReserve0D", handleMsgSysReserve0D},
+		{"handleMsgSysReserve0E", handleMsgSysReserve0E},
+		{"handleMsgSysReserve4A", handleMsgSysReserve4A},
+		{"handleMsgSysReserve4B", handleMsgSysReserve4B},
+		{"handleMsgSysReserve4C", handleMsgSysReserve4C},
+		{"handleMsgSysReserve4D", handleMsgSysReserve4D},
+		{"handleMsgSysReserve4E", handleMsgSysReserve4E},
+		{"handleMsgSysReserve4F", handleMsgSysReserve4F},
+		{"handleMsgSysReserve5C", handleMsgSysReserve5C},
+		{"handleMsgSysReserve5E", handleMsgSysReserve5E},
+		{"handleMsgSysReserve5F", handleMsgSysReserve5F},
+		{"handleMsgSysReserve71", handleMsgSysReserve71},
+		{"handleMsgSysReserve72", handleMsgSysReserve72},
+		{"handleMsgSysReserve73", handleMsgSysReserve73},
+		{"handleMsgSysReserve74", handleMsgSysReserve74},
+		{"handleMsgSysReserve75", handleMsgSysReserve75},
+		{"handleMsgSysReserve76", handleMsgSysReserve76},
+		{"handleMsgSysReserve77", handleMsgSysReserve77},
+		{"handleMsgSysReserve78", handleMsgSysReserve78},
+		{"handleMsgSysReserve79", handleMsgSysReserve79},
+		{"handleMsgSysReserve7A", handleMsgSysReserve7A},
+		{"handleMsgSysReserve7B", handleMsgSysReserve7B},
+		{"handleMsgSysReserve7C", handleMsgSysReserve7C},
+		{"handleMsgSysReserve7E", handleMsgSysReserve7E},
+		{"handleMsgMhfReserve10F", handleMsgMhfReserve10F},
+		{"handleMsgSysReserve180", handleMsgSysReserve180},
+		{"handleMsgSysReserve18E", handleMsgSysReserve18E},
+		{"handleMsgSysReserve18F", handleMsgSysReserve18F},
+		{"handleMsgSysReserve19E", handleMsgSysReserve19E},
+		{"handleMsgSysReserve19F", handleMsgSysReserve19F},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			defer func() {
+				if r := recover(); r != nil {
+					t.Errorf("%s panicked: %v", tt.name, r)
+				}
+			}()
+
+			// Call with nil packet - empty handlers should handle this
+			tt.handler(session, nil)
+		})
+	}
+}
+
+// Test reserve handlers are registered in handler table
+
+func TestReserveHandlersRegistered(t *testing.T) {
+	if handlerTable == nil {
+		t.Fatal("handlerTable should be initialized")
+	}
+
+	// Check that reserve handlers exist in the table
+	reserveHandlerCount := 0
+	for _, handler := range handlerTable {
+		if handler != nil {
+			reserveHandlerCount++
+		}
+	}
+
+	if reserveHandlerCount < 50 {
+		t.Errorf("Expected at least 50 handlers registered, got %d", reserveHandlerCount)
+	}
+}