refactor: 将redis各个业务分离

backend/internal/middleware/redis/cache.go

@@ -0,0 +1,18 @@
+package redis
+
+import (
+	"context"
+	"time"
+)
+
+func (c *Client) GetBytes(ctx context.Context, key string) ([]byte, error) {
+	return c.rdb.Get(ctx, key).Bytes()
+}
+
+func (c *Client) SetBytes(ctx context.Context, key string, value []byte, ttl time.Duration) error {
+	return c.rdb.Set(ctx, key, value, ttl).Err()
+}
+
+func (c *Client) Del(ctx context.Context, key string) error {
+	return c.rdb.Del(ctx, key).Err()
+}