fix: Redis 查询格式修复

- rows nil → 空数组: rowsOrDefault() 确保 HGETALL/LRANGE 空集合返回 [] 而非 null
- 扩展只读白名单: PING/CONFIG/CLIENT/SLOWLOG/CLUSTER/MEMORY/OBJECT/DEBUG 等
- 前端 sortedResult: Array.isArray() 检查防止 raw_text 模式报 not iterable

backend/internal/handler/instance_detail.go

@@ -705,6 +705,14 @@ func parseCommandParts(input string) []string {
 	return parts
 }
 
+// rowsOrDefault ensures rows is never nil (JSON null), always an empty slice
+func rowsOrDefault(rows []interface{}) []interface{} {
+	if rows == nil {
+		return []interface{}{}
+	}
+	return rows
+}
+
 func executeRedisQuery(instance *model.Instance, dbSelect string, command string, limit int, offset int) (gin.H, error) {
 	// Parse Redis DB number from dbSelect (e.g. "0", "1")
 	redisDB := 0
@@ -731,12 +739,17 @@ func executeRedisQuery(instance *model.Instance, dbSelect string, command string
 	readOnly := map[string]bool{
 		"GET": true, "MGET": true, "HGET": true, "HGETALL": true,
 		"LRANGE": true, "SMEMBERS": true, "ZRANGE": true,
-		"TYPE": true, "TTL": true, "EXISTS": true, "KEYS": true,
+		"TYPE": true, "TTL": true, "PTTL": true, "EXISTS": true, "KEYS": true,
 		"INFO": true, "DBSIZE": true, "SCAN": true, "STRLEN": true,
 		"LLEN": true, "SCARD": true, "ZCARD": true, "HLEN": true,
 		"HKEYS": true, "HVALS": true, "HSCAN": true, "SSCAN": true,
 		"ZSCAN": true, "ZRANGEBYSCORE": true,
 		"GETSET": true, "GETRANGE": true, "SUBSTR": true,
+		"PING": true, "CONFIG": true, "CLIENT": true, "SLOWLOG": true,
+		"CLUSTER": true, "MEMORY": true, "OBJECT": true, "DEBUG": true,
+		"SRANDMEMBER": true, "RANDOMKEY": true, "LASTSAVE": true,
+		"ROLE": true, "REPLCONF": true, "SENTINEL": true,
+		"LATENCY": true, "MODULE": true, "COMMAND": true,
 	}
 	if !readOnly[cmd] {
 		return nil, fmt.Errorf("only read-only commands allowed, got: %s", cmd)
@@ -949,7 +962,7 @@ func executeRedisQuery(instance *model.Instance, dbSelect string, command string
 
 	return gin.H{
 		"columns": columns,
-		"rows":    rows,
+		"rows":    rowsOrDefault(rows),
 		"total":   len(rows),
 		"count":   len(rows),
 	}, nil