refactor: standardize logging on zap across all packages

Replace all fmt.Printf/Println and log.Printf/Fatal with structured
zap.Logger calls to eliminate inconsistent logging (anti-pattern #12).

- network/crypt_conn: inject logger via NewCryptConn, replace 6 fmt calls
- signserver/session: use existing s.logger for debug packet dumps
- entranceserver: use s.logger for inbound/outbound debug logging
- api/utils: accept logger param in verifyPath, replace fmt.Println
- api/endpoints: use s.logger for screenshot path diagnostics
- config: replace log.Fatal with error return in getOutboundIP4
- deltacomp: replace log.Printf with zap.L() global logger

config/config_test.go

@@ -108,14 +108,14 @@ func TestVersionStringsContent(t *testing.T) {
 		index    int
 		expected string
 	}{
-		{0, "S1.0"},    // S1
-		{14, "S10"},    // S10
-		{15, "FW.1"},   // F1
-		{19, "FW.5"},   // F5
-		{20, "G1"},     // G1
-		{38, "Z1"},     // Z1
-		{39, "Z2"},     // Z2
-		{40, "ZZ"},     // ZZ
+		{0, "S1.0"},  // S1
+		{14, "S10"},  // S10
+		{15, "FW.1"}, // F1
+		{19, "FW.5"}, // F5
+		{20, "G1"},   // G1
+		{38, "Z1"},   // Z1
+		{39, "Z2"},   // Z2
+		{40, "ZZ"},   // ZZ
 	}
 
 	for _, tt := range tests {
@@ -127,7 +127,10 @@ func TestVersionStringsContent(t *testing.T) {
 
 // TestGetOutboundIP4 tests IP detection
 func TestGetOutboundIP4(t *testing.T) {
-	ip := getOutboundIP4()
+	ip, err := getOutboundIP4()
+	if err != nil {
+		t.Fatalf("getOutboundIP4() returned error: %v", err)
+	}
 	if ip == nil {
 		t.Error("getOutboundIP4() returned nil IP")
 	}
@@ -276,17 +279,17 @@ func TestDebugOptions(t *testing.T) {
 // TestGameplayOptions verifies GameplayOptions struct
 func TestGameplayOptions(t *testing.T) {
 	opts := GameplayOptions{
-		MinFeatureWeapons:       2,
-		MaxFeatureWeapons:       10,
-		MaximumNP:               999999,
-		MaximumRP:               9999,
-		MaximumFP:               999999999,
-		MezFesSoloTickets:       100,
-		MezFesGroupTickets:      50,
-		DisableHunterNavi:       true,
-		EnableKaijiEvent:        true,
-		EnableHiganjimaEvent:    false,
-		EnableNierEvent:         false,
+		MinFeatureWeapons:    2,
+		MaxFeatureWeapons:    10,
+		MaximumNP:            999999,
+		MaximumRP:            9999,
+		MaximumFP:            999999999,
+		MezFesSoloTickets:    100,
+		MezFesGroupTickets:   50,
+		DisableHunterNavi:    true,
+		EnableKaijiEvent:     true,
+		EnableHiganjimaEvent: false,
+		EnableNierEvent:      false,
 	}
 
 	if opts.MinFeatureWeapons != 2 {
@@ -486,12 +489,12 @@ func TestEntrance(t *testing.T) {
 // TestEntranceServerInfo verifies EntranceServerInfo struct
 func TestEntranceServerInfo(t *testing.T) {
 	info := EntranceServerInfo{
-		IP:                "192.168.1.1",
-		Type:              1,
-		Season:            0,
-		Recommended:       0,
-		Name:              "Server 1",
-		Description:       "Main server",
+		IP:                 "192.168.1.1",
+		Type:               1,
+		Season:             0,
+		Recommended:        0,
+		Name:               "Server 1",
+		Description:        "Main server",
 		AllowedClientFlags: 4096,
 		Channels: []EntranceChannelInfo{
 			{Port: 10001, MaxPlayers: 4, CurrentPlayers: 2},
@@ -624,9 +627,9 @@ func TestGameplayOptionsConstraints(t *testing.T) {
 		{
 			name: "valid multipliers",
 			opts: GameplayOptions{
-				HRPMultiplier:     1.5,
-				GRPMultiplier:     1.2,
-				ZennyMultiplier:   1.0,
+				HRPMultiplier:      1.5,
+				GRPMultiplier:      1.2,
+				ZennyMultiplier:    1.0,
 				MaterialMultiplier: 1.3,
 			},
 			ok: true,
@@ -671,7 +674,7 @@ func TestModeValueRanges(t *testing.T) {
 // TestConfigDefaults tests default configuration creation
 func TestConfigDefaults(t *testing.T) {
 	cfg := &Config{
-		ClientMode:   "ZZ",
+		ClientMode:     "ZZ",
 		RealClientMode: ZZ,
 	}
 
@@ -696,7 +699,6 @@ func BenchmarkModeString(b *testing.B) {
 func BenchmarkGetOutboundIP4(b *testing.B) {
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		_ = getOutboundIP4()
+		_, _ = getOutboundIP4()
 	}
 }
-