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

@@ -28,26 +28,26 @@ func newVoiceMocks(t *testing.T) *voiceMocks {
 	m := &voiceMocks{}
 
 	m.STT = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		json.NewEncoder(w).Encode(map[string]string{"text": "What is the weather today?"})
+		_ = json.NewEncoder(w).Encode(map[string]string{"text": "What is the weather today?"})
 	}))
 	t.Cleanup(m.STT.Close)
 
 	m.Embeddings = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		json.NewEncoder(w).Encode(map[string]any{
+		_ = json.NewEncoder(w).Encode(map[string]any{
 			"data": []map[string]any{{"embedding": []float64{0.5, 0.6, 0.7}}},
 		})
 	}))
 	t.Cleanup(m.Embeddings.Close)
 
 	m.Reranker = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		json.NewEncoder(w).Encode(map[string]any{
+		_ = json.NewEncoder(w).Encode(map[string]any{
 			"results": []map[string]any{{"index": 0, "relevance_score": 0.88}},
 		})
 	}))
 	t.Cleanup(m.Reranker.Close)
 
 	m.LLM = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		json.NewEncoder(w).Encode(map[string]any{
+		_ = json.NewEncoder(w).Encode(map[string]any{
 			"choices": []map[string]any{
 				{"message": map[string]any{"content": "Sunny with a high of 72."}},
 			},
@@ -56,7 +56,7 @@ func newVoiceMocks(t *testing.T) *voiceMocks {
 	t.Cleanup(m.LLM.Close)
 
 	m.TTS = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Write(make([]byte, 8000)) // simulated audio
+		_, _ = w.Write(make([]byte, 8000)) // simulated audio
 	}))
 	t.Cleanup(m.TTS.Close)
 
@@ -122,7 +122,7 @@ func TestVoicePipeline_FullFlow(t *testing.T) {
 func TestVoicePipeline_STTFailure(t *testing.T) {
 	failSTT := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(500)
-		w.Write([]byte("model not loaded"))
+		_, _ = w.Write([]byte("model not loaded"))
 	}))
 	defer failSTT.Close()
 
@@ -136,7 +136,7 @@ func TestVoicePipeline_STTFailure(t *testing.T) {
 func TestVoicePipeline_TTSLargeResponse(t *testing.T) {
 	// TTS that returns 1 MB of audio.
 	bigTTS := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Write(make([]byte, 1<<20))
+		_, _ = w.Write(make([]byte, 1<<20))
 	}))
 	defer bigTTS.Close()
 
@@ -156,17 +156,17 @@ func TestVoicePipeline_TTSLargeResponse(t *testing.T) {
 
 func BenchmarkVoicePipeline_Full(b *testing.B) {
 	sttSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Write([]byte(`{"text":"hello"}`))
+		_, _ = w.Write([]byte(`{"text":"hello"}`))
 	}))
 	defer sttSrv.Close()
 
 	llmSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Write([]byte(`{"choices":[{"message":{"content":"answer"}}]}`))
+		_, _ = w.Write([]byte(`{"choices":[{"message":{"content":"answer"}}]}`))
 	}))
 	defer llmSrv.Close()
 
 	ttsSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Write(make([]byte, 4000))
+		_, _ = w.Write(make([]byte, 4000))
 	}))
 	defer ttsSrv.Close()
 
@@ -178,8 +178,8 @@ func BenchmarkVoicePipeline_Full(b *testing.B) {
 
 	b.ResetTimer()
 	for b.Loop() {
-		stt.Transcribe(ctx, audio, "en")
-		llm.Generate(ctx, "question", "", "")
-		tts.Synthesize(ctx, "answer", "en", "")
+		_, _ = stt.Transcribe(ctx, audio, "en")
+		_, _ = llm.Generate(ctx, "question", "", "")
+		_, _ = tts.Synthesize(ctx, "answer", "en", "")
 	}
 }