Go: fix list services (#17664)

### Summary

1. Fix admin list services;
2. Fix admin show service 'service_name';

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/engine/engine.go

@@ -66,14 +66,14 @@ type DocEngine interface {
 	GetAggregation(chunks []map[string]interface{}, fieldName string) []map[string]interface{}
 	GetHighlight(chunks []map[string]interface{}, keywords []string, fieldName string) map[string]string
 
-	// Run SQL
+	// RunSQL runs a SQL query
 	RunSQL(ctx context.Context, tableName string, sqlText string, kbIDs []string, format string) ([]map[string]interface{}, error)
 
 	GetChunkIDs(chunks []map[string]interface{}) []string
 	KNNScores(ctx context.Context, chunks []map[string]interface{}, queryVector []float64, topK int) (map[string]interface{}, error)
 	GetScores(searchResult map[string]interface{}) map[string]float64
 
-	// Health check
+	// Ping check the engine is alive
 	Ping(ctx context.Context) error
 	Close() error
 
@@ -101,6 +101,7 @@ func Type(docEngine DocEngine) EngineType {
 
 type MessageQueue interface {
 	Init() error
+	Type() string
 	InitConsumer(subject string) error
 	PublishTask(subject string, payload []byte) error
 	GetMessages(messageCount int) ([]common.TaskHandle, error)

internal/engine/nats/nats.go

@@ -97,6 +97,10 @@ func (n *NatsEngine) Init() error {
 	return nil
 }
 
+func (n *NatsEngine) Type() string {
+	return "nats"
+}
+
 func (n *NatsEngine) PublishTask(subject string, payload []byte) error {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()

internal/engine/redis/redis.go

@@ -374,7 +374,7 @@ func (r *Client) SetNX(key string, value string, exp time.Duration) bool {
 	return ok
 }
 
-// GetOrCreateSecretKey atomically retrieves an existing key or creates a new one
+// GetOrCreateKey atomically retrieves an existing key or creates a new one
 // Uses Redis SETNX command to ensure atomicity across multiple goroutines/processes
 func (r *Client) GetOrCreateKey(key string, value string) (string, error) {
 	if r.client == nil {