feat: 配置 golangci-lint 静态分析并修复存量违规

- 新增 backend/.golangci.yml 配置 12 个 linter（forbidigo、errorlint、errcheck、staticcheck、revive、gocritic、gosec、bodyclose、noctx、nilerr、goimports、gocyclo）
- 新增 lefthook.yml 配置 pre-commit hook 自动运行 lint
- 修复存量代码违规：errors.Is/As 替换、zap.Error 替换、import 排序、errcheck 修复
- 更新 README 补充编码规范说明
- 归档 backend-code-lint 变更

backend/internal/conversion/anthropic/adapter_test.go

@@ -2,6 +2,7 @@ package anthropic
 
 import (
 	"encoding/json"
+	"errors"
 	"testing"
 
 	"nex/backend/internal/conversion"
@@ -52,10 +53,10 @@ func TestAdapter_BuildUrl(t *testing.T) {
 	a := NewAdapter()
 
 	tests := []struct {
-		name         string
-		nativePath   string
+		name          string
+		nativePath    string
 		interfaceType conversion.InterfaceType
-		expected     string
+		expected      string
 	}{
 		{"聊天", "/v1/messages", conversion.InterfaceTypeChat, "/v1/messages"},
 		{"模型", "/v1/models", conversion.InterfaceTypeModels, "/v1/models"},
@@ -102,9 +103,9 @@ func TestAdapter_SupportsInterface(t *testing.T) {
 	a := NewAdapter()
 
 	tests := []struct {
-		name         string
+		name          string
 		interfaceType conversion.InterfaceType
-		expected     bool
+		expected      bool
 	}{
 		{"聊天", conversion.InterfaceTypeChat, true},
 		{"模型", conversion.InterfaceTypeModels, true},
@@ -141,8 +142,8 @@ func TestAdapter_UnsupportedEmbedding(t *testing.T) {
 	t.Run("解码嵌入请求", func(t *testing.T) {
 		_, err := a.DecodeEmbeddingRequest([]byte(`{}`))
 		require.Error(t, err)
-		convErr, ok := err.(*conversion.ConversionError)
-		require.True(t, ok)
+		var convErr *conversion.ConversionError
+		require.ErrorAs(t, err, &convErr)
 		assert.Equal(t, conversion.ErrorCodeInterfaceNotSupported, convErr.Code)
 	})
 
@@ -150,24 +151,24 @@ func TestAdapter_UnsupportedEmbedding(t *testing.T) {
 		provider := conversion.NewTargetProvider("https://api.anthropic.com", "key", "claude-3")
 		_, err := a.EncodeEmbeddingRequest(&canonical.CanonicalEmbeddingRequest{}, provider)
 		require.Error(t, err)
-		convErr, ok := err.(*conversion.ConversionError)
-		require.True(t, ok)
+		var convErr *conversion.ConversionError
+		require.True(t, errors.As(err, &convErr))
 		assert.Equal(t, conversion.ErrorCodeInterfaceNotSupported, convErr.Code)
 	})
 
 	t.Run("解码嵌入响应", func(t *testing.T) {
 		_, err := a.DecodeEmbeddingResponse([]byte(`{}`))
 		require.Error(t, err)
-		convErr, ok := err.(*conversion.ConversionError)
-		require.True(t, ok)
+		var convErr *conversion.ConversionError
+		require.ErrorAs(t, err, &convErr)
 		assert.Equal(t, conversion.ErrorCodeInterfaceNotSupported, convErr.Code)
 	})
 
 	t.Run("编码嵌入响应", func(t *testing.T) {
 		_, err := a.EncodeEmbeddingResponse(&canonical.CanonicalEmbeddingResponse{})
 		require.Error(t, err)
-		convErr, ok := err.(*conversion.ConversionError)
-		require.True(t, ok)
+		var convErr *conversion.ConversionError
+		require.ErrorAs(t, err, &convErr)
 		assert.Equal(t, conversion.ErrorCodeInterfaceNotSupported, convErr.Code)
 	})
 }
@@ -178,8 +179,8 @@ func TestAdapter_UnsupportedRerank(t *testing.T) {
 	t.Run("解码重排序请求", func(t *testing.T) {
 		_, err := a.DecodeRerankRequest([]byte(`{}`))
 		require.Error(t, err)
-		convErr, ok := err.(*conversion.ConversionError)
-		require.True(t, ok)
+		var convErr *conversion.ConversionError
+		require.ErrorAs(t, err, &convErr)
 		assert.Equal(t, conversion.ErrorCodeInterfaceNotSupported, convErr.Code)
 	})
 
@@ -187,24 +188,24 @@ func TestAdapter_UnsupportedRerank(t *testing.T) {
 		provider := conversion.NewTargetProvider("https://api.anthropic.com", "key", "claude-3")
 		_, err := a.EncodeRerankRequest(&canonical.CanonicalRerankRequest{}, provider)
 		require.Error(t, err)
-		convErr, ok := err.(*conversion.ConversionError)
-		require.True(t, ok)
+		var convErr *conversion.ConversionError
+		require.ErrorAs(t, err, &convErr)
 		assert.Equal(t, conversion.ErrorCodeInterfaceNotSupported, convErr.Code)
 	})
 
 	t.Run("解码重排序响应", func(t *testing.T) {
 		_, err := a.DecodeRerankResponse([]byte(`{}`))
 		require.Error(t, err)
-		convErr, ok := err.(*conversion.ConversionError)
-		require.True(t, ok)
+		var convErr *conversion.ConversionError
+		require.ErrorAs(t, err, &convErr)
 		assert.Equal(t, conversion.ErrorCodeInterfaceNotSupported, convErr.Code)
 	})
 
 	t.Run("编码重排序响应", func(t *testing.T) {
 		_, err := a.EncodeRerankResponse(&canonical.CanonicalRerankResponse{})
 		require.Error(t, err)
-		convErr, ok := err.(*conversion.ConversionError)
-		require.True(t, ok)
+		var convErr *conversion.ConversionError
+		require.ErrorAs(t, err, &convErr)
 		assert.Equal(t, conversion.ErrorCodeInterfaceNotSupported, convErr.Code)
 	})
 }