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

@@ -150,12 +150,12 @@ func TestTranscriptionE2E_MockWhisper(t *testing.T) {
 			if err != nil {
 				t.Errorf("missing 'file' field: %v", err)
 			} else {
-				file.Close()
+				_ = file.Close()
 			}
 		}
 
 		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode(map[string]string{"text": "hello world"})
+		_ = json.NewEncoder(w).Encode(map[string]string{"text": "hello world"})
 	}))
 	defer whisperSrv.Close()
 
@@ -166,20 +166,20 @@ func TestTranscriptionE2E_MockWhisper(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	part.Write(make([]byte, 8000)) // simulated audio
-	writer.Close()
+	_, _ = part.Write(make([]byte, 8000)) // simulated audio
+	_ = writer.Close()
 
 	resp, err := http.Post(whisperSrv.URL+"/v1/audio/transcriptions", writer.FormDataContentType(), &buf)
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 	if resp.StatusCode != 200 {
 		t.Errorf("status = %d", resp.StatusCode)
 	}
 
 	var result map[string]string
-	json.NewDecoder(resp.Body).Decode(&result)
+	_ = json.NewDecoder(resp.Body).Decode(&result)
 	if result["text"] != "hello world" {
 		t.Errorf("text = %q, want %q", result["text"], "hello world")
 	}

main.go

@@ -264,8 +264,8 @@ func main() {
 		if err != nil {
 			return "", err
 		}
-		part.Write(audioData)
-		w.Close()
+		_, _ = part.Write(audioData)
+		_ = w.Close()
 
 		req, err := http.NewRequestWithContext(ctx, http.MethodPost, whisperURL+"/v1/audio/transcriptions", &buf)
 		if err != nil {
@@ -277,7 +277,7 @@ func main() {
 		if err != nil {
 			return "", fmt.Errorf("whisper request: %w", err)
 		}
-		defer resp.Body.Close()
+		defer func() { _ = resp.Body.Close() }()
 		body, _ := io.ReadAll(resp.Body)
 
 		if resp.StatusCode >= 400 {
@@ -335,7 +335,7 @@ func main() {
 				State:            state,
 			}
 			packed, _ := msgpack.Marshal(result)
-			nc.Conn().Publish(fmt.Sprintf("%s.%s", transcriptionSubjectPrefix, sessionID), packed)
+			_ = nc.Conn().Publish(fmt.Sprintf("%s.%s", transcriptionSubjectPrefix, sessionID), packed)
 			slog.Info("published transcription", "session", sessionID, "seq", seq)
 		}
 
@@ -448,7 +448,7 @@ func main() {
 					SpeakerID: buffer.speakerID,
 				}
 				packed, _ := msgpack.Marshal(interruptMsg)
-				nc.Conn().Publish(fmt.Sprintf("%s.%s", transcriptionSubjectPrefix, sessionID), packed)
+				_ = nc.Conn().Publish(fmt.Sprintf("%s.%s", transcriptionSubjectPrefix, sessionID), packed)
 				slog.Info("published interrupt", "session", sessionID)
 				buffer.setState(stateListening)
 			}

main_test.go

@@ -155,7 +155,7 @@ func TestTranscribeHTTP(t *testing.T) {
 			t.Errorf("expected POST, got %s", r.Method)
 		}
 		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode(map[string]string{"text": "hello world"})
+		_ = json.NewEncoder(w).Encode(map[string]string{"text": "hello world"})
 	}))
 	defer ts.Close()
 
@@ -164,7 +164,7 @@ func TestTranscribeHTTP(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", resp.StatusCode)
 	}