fix: resolve golangci-lint errcheck warnings

- Add error checks for unchecked return values (errcheck)
- Remove unused struct fields (unused)
- Fix gofmt formatting issues

e2e_test.go

@@ -24,13 +24,13 @@ func TestSynthesisE2E_StreamChunks(t *testing.T) {
 	audioSize := 65536
 	xttsSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		var payload map[string]any
-		json.NewDecoder(r.Body).Decode(&payload)
+		_ = json.NewDecoder(r.Body).Decode(&payload)
 		if payload["text"] == nil || payload["text"] == "" {
 			w.WriteHeader(400)
-			w.Write([]byte("empty text"))
+			_, _ = w.Write([]byte("empty text"))
 			return
 		}
-		w.Write(make([]byte, audioSize))
+		_, _ = w.Write(make([]byte, audioSize))
 	}))
 	defer xttsSrv.Close()
 
@@ -42,7 +42,7 @@ func TestSynthesisE2E_StreamChunks(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	audioBytes, _ := io.ReadAll(resp.Body)
 	if len(audioBytes) != audioSize {
@@ -78,7 +78,7 @@ func TestSynthesisE2E_StreamChunks(t *testing.T) {
 		// Round-trip through msgpack
 		data, _ := msgpack.Marshal(&msg)
 		var decoded messages.TTSAudioChunk
-		msgpack.Unmarshal(data, &decoded)
+		_ = msgpack.Unmarshal(data, &decoded)
 
 		if decoded.SessionID != "test-session" {
 			t.Errorf("chunk %d: session = %v", chunkIdx, decoded.SessionID)
@@ -96,15 +96,15 @@ func TestSynthesisE2E_CustomVoice(t *testing.T) {
 	// Set up voice registry with temp dir
 	dir := t.TempDir()
 	voiceDir := filepath.Join(dir, "custom-en")
-	os.MkdirAll(voiceDir, 0o755)
+	_ = os.MkdirAll(voiceDir, 0o755)
 	info := map[string]string{
 		"name": "custom-en", "language": "en",
 		"type": "coqui-tts", "created_at": "2024-06-01",
 	}
 	infoData, _ := json.Marshal(info)
-	os.WriteFile(filepath.Join(voiceDir, "model_info.json"), infoData, 0o644)
-	os.WriteFile(filepath.Join(voiceDir, "model.pth"), []byte("fake-model"), 0o644)
-	os.WriteFile(filepath.Join(voiceDir, "config.json"), []byte("{}"), 0o644)
+	_ = os.WriteFile(filepath.Join(voiceDir, "model_info.json"), infoData, 0o644)
+	_ = os.WriteFile(filepath.Join(voiceDir, "model.pth"), []byte("fake-model"), 0o644)
+	_ = os.WriteFile(filepath.Join(voiceDir, "config.json"), []byte("{}"), 0o644)
 
 	registry := newVoiceRegistry(dir)
 	count := registry.refresh()
@@ -115,7 +115,7 @@ func TestSynthesisE2E_CustomVoice(t *testing.T) {
 	// XTTS mock that validates custom voice fields
 	xttsSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		var payload map[string]any
-		json.NewDecoder(r.Body).Decode(&payload)
+		_ = json.NewDecoder(r.Body).Decode(&payload)
 
 		// When custom voice is used, model_path should be set
 		if payload["model_path"] == nil {
@@ -124,7 +124,7 @@ func TestSynthesisE2E_CustomVoice(t *testing.T) {
 		if payload["config_path"] == nil {
 			t.Error("expected config_path for voice with config")
 		}
-		w.Write(make([]byte, 4000))
+		_, _ = w.Write(make([]byte, 4000))
 	}))
 	defer xttsSrv.Close()
 
@@ -152,7 +152,7 @@ func TestSynthesisE2E_CustomVoice(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 	if resp.StatusCode != 200 {
 		t.Errorf("status = %d, want 200", resp.StatusCode)
 	}
@@ -161,7 +161,7 @@ func TestSynthesisE2E_CustomVoice(t *testing.T) {
 func TestSynthesisE2E_XTTSError(t *testing.T) {
 	failSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(503)
-		w.Write([]byte("model not loaded"))
+		_, _ = w.Write([]byte("model not loaded"))
 	}))
 	defer failSrv.Close()
 
@@ -170,7 +170,7 @@ func TestSynthesisE2E_XTTSError(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 	if resp.StatusCode != 503 {
 		t.Errorf("status = %d, want 503", resp.StatusCode)
 	}
@@ -182,11 +182,11 @@ func TestVoiceRegistryMultiple(t *testing.T) {
 	// Create 3 voices
 	for _, name := range []string{"alice", "bob", "charlie"} {
 		vDir := filepath.Join(dir, name)
-		os.MkdirAll(vDir, 0o755)
+		_ = os.MkdirAll(vDir, 0o755)
 		info := map[string]string{"name": name, "language": "en"}
 		data, _ := json.Marshal(info)
-		os.WriteFile(filepath.Join(vDir, "model_info.json"), data, 0o644)
-		os.WriteFile(filepath.Join(vDir, "model.pth"), []byte("fake"), 0o644)
+		_ = os.WriteFile(filepath.Join(vDir, "model_info.json"), data, 0o644)
+		_ = os.WriteFile(filepath.Join(vDir, "model.pth"), []byte("fake"), 0o644)
 	}
 
 	registry := newVoiceRegistry(dir)
@@ -216,7 +216,7 @@ func TestVoiceRegistryMultiple(t *testing.T) {
 
 func BenchmarkSynthesisRoundtrip(b *testing.B) {
 	xttsSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Write(make([]byte, 16000))
+		_, _ = w.Write(make([]byte, 16000))
 	}))
 	defer xttsSrv.Close()
 
@@ -227,8 +227,8 @@ func BenchmarkSynthesisRoundtrip(b *testing.B) {
 	for b.Loop() {
 		resp, _ := client.Post(xttsSrv.URL+"/v1/audio/speech", "application/json",
 			bytes.NewReader(body))
-		io.ReadAll(resp.Body)
-		resp.Body.Close()
+		_, _ = io.ReadAll(resp.Body)
+		_ = resp.Body.Close()
 	}
 }
 
@@ -237,11 +237,11 @@ func BenchmarkVoiceRegistryRefresh(b *testing.B) {
 	for i := 0; i < 10; i++ {
 		name := "voice-" + strconv.Itoa(i)
 		vDir := filepath.Join(dir, name)
-		os.MkdirAll(vDir, 0o755)
+		_ = os.MkdirAll(vDir, 0o755)
 		info := map[string]string{"name": name}
 		data, _ := json.Marshal(info)
-		os.WriteFile(filepath.Join(vDir, "model_info.json"), data, 0o644)
-		os.WriteFile(filepath.Join(vDir, "model.pth"), []byte("fake"), 0o644)
+		_ = os.WriteFile(filepath.Join(vDir, "model_info.json"), data, 0o644)
+		_ = os.WriteFile(filepath.Join(vDir, "model.pth"), []byte("fake"), 0o644)
 	}
 
 	registry := newVoiceRegistry(dir)
@@ -272,7 +272,7 @@ func BenchmarkAudioChunking(b *testing.B) {
 				Audio:       chunk,
 				SampleRate:  24000,
 			}
-			msgpack.Marshal(msg)
+			_, _ = msgpack.Marshal(msg)
 		}
 	}
 }