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

@@ -30,7 +30,7 @@ t.Helper()
 m := &mockBackends{}
 
 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{0.1, 0.2, 0.3, 0.4}},
 },
@@ -39,7 +39,7 @@ json.NewEncoder(w).Encode(map[string]any{
 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": 0.95},
 },
@@ -49,8 +49,8 @@ t.Cleanup(m.Reranker.Close)
 
 m.LLM = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 var req map[string]any
-json.NewDecoder(r.Body).Decode(&req)
-json.NewEncoder(w).Encode(map[string]any{
+_ = json.NewDecoder(r.Body).Decode(&req)
+_ = json.NewEncoder(w).Encode(map[string]any{
 "choices": []map[string]any{
 {"message": map[string]any{
 "content": "Paris is the capital of France.",
@@ -61,7 +61,7 @@ json.NewEncoder(w).Encode(map[string]any{
 t.Cleanup(m.LLM.Close)
 
 m.TTS = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-w.Write([]byte{0xDE, 0xAD, 0xBE, 0xEF})
+_, _ = w.Write([]byte{0xDE, 0xAD, 0xBE, 0xEF})
 }))
 t.Cleanup(m.TTS.Close)
 
@@ -148,7 +148,7 @@ func TestChatPipeline_LLMTimeout(t *testing.T) {
 // Simulate slow LLM.
 slow := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 time.Sleep(200 * time.Millisecond)
-json.NewEncoder(w).Encode(map[string]any{
+_ = json.NewEncoder(w).Encode(map[string]any{
 "choices": []map[string]any{
 {"message": map[string]any{"content": "late response"}},
 },
@@ -204,7 +204,7 @@ func TestChatPipeline_TypedDecoding(t *testing.T) {
 
 func BenchmarkChatPipeline_LLMOnly(b *testing.B) {
 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()
 
@@ -213,23 +213,23 @@ ctx := context.Background()
 
 b.ResetTimer()
 for b.Loop() {
-llm.Generate(ctx, "question", "", "")
+_, _ = llm.Generate(ctx, "question", "", "")
 }
 }
 
 func BenchmarkChatPipeline_RAGFlow(b *testing.B) {
 embedSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-w.Write([]byte(`{"data":[{"embedding":[0.1,0.2]}]}`))
+_, _ = w.Write([]byte(`{"data":[{"embedding":[0.1,0.2]}]}`))
 }))
 defer embedSrv.Close()
 
 rerankSrv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-w.Write([]byte(`{"results":[{"index":0,"relevance_score":0.9}]}`))
+_, _ = w.Write([]byte(`{"results":[{"index":0,"relevance_score":0.9}]}`))
 }))
 defer rerankSrv.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()
 
@@ -240,8 +240,8 @@ ctx := context.Background()
 
 b.ResetTimer()
 for b.Loop() {
-embed.EmbedSingle(ctx, "question")
-rerank.Rerank(ctx, "question", []string{"doc1", "doc2"}, 2)
-llm.Generate(ctx, "question", "context", "")
+_, _ = embed.EmbedSingle(ctx, "question")
+_, _ = rerank.Rerank(ctx, "question", []string{"doc1", "doc2"}, 2)
+_, _ = llm.Generate(ctx, "question", "context", "")
 }
 }