feat: add image management functionality

- Implemented image folder repository with CRUD operations.
- Added image reference repository for managing image references to articles.
- Created image repository for handling image assets, including listing, inserting, updating, and deleting images.
- Introduced image usage repository to track storage usage and quotas for tenants.
- Added SQL queries for image assets, folders, references, and usage.
- Developed image handler for HTTP endpoints to manage images and folders.
- Created database migration scripts for image-related tables and structures.

server/internal/shared/objectstorage/aliyun.go

@@ -158,6 +158,36 @@ func (c *aliyunClient) GetBytes(ctx context.Context, objectKey string) ([]byte,
 	return data, nil
 }
 
+func (c *aliyunClient) Exists(ctx context.Context, objectKey string) (bool, error) {
+	if err := c.Validate(); err != nil {
+		return false, err
+	}
+	if strings.TrimSpace(objectKey) == "" {
+		return false, nil
+	}
+
+	bucket, err := c.client.Bucket(c.bucket)
+	if err != nil {
+		c.logError(ctx, "aliyun get bucket failed",
+			zap.String("bucket", c.bucket),
+			zap.String("object_key", objectKey),
+			zap.Error(err),
+		)
+		return false, fmt.Errorf("get aliyun bucket: %w", err)
+	}
+
+	exists, err := bucket.IsObjectExist(objectKey)
+	if err != nil {
+		c.logError(ctx, "aliyun stat object failed",
+			zap.String("bucket", c.bucket),
+			zap.String("object_key", objectKey),
+			zap.Error(err),
+		)
+		return false, fmt.Errorf("stat aliyun object: %w", err)
+	}
+	return exists, nil
+}
+
 func (c *aliyunClient) Delete(ctx context.Context, objectKey string) error {
 	if err := c.Validate(); err != nil {
 		return err

server/internal/shared/objectstorage/client.go

@@ -17,6 +17,7 @@ type Client interface {
 	Validate() error
 	PutBytes(ctx context.Context, objectKey string, content []byte, contentType string) error
 	GetBytes(ctx context.Context, objectKey string) ([]byte, error)
+	Exists(ctx context.Context, objectKey string) (bool, error)
 	Delete(ctx context.Context, objectKey string) error
 	PublicURL(objectKey string) (string, error)
 }
@@ -54,6 +55,10 @@ func (c disabledClient) GetBytes(context.Context, string) ([]byte, error) {
 	return nil, c.Validate()
 }
 
+func (c disabledClient) Exists(context.Context, string) (bool, error) {
+	return false, c.Validate()
+}
+
 func (c disabledClient) Delete(context.Context, string) error {
 	return c.Validate()
 }

server/internal/shared/objectstorage/minio.go

@@ -135,6 +135,32 @@ func (c *minioClient) GetBytes(ctx context.Context, objectKey string) ([]byte, e
 	return data, nil
 }
 
+func (c *minioClient) Exists(ctx context.Context, objectKey string) (bool, error) {
+	if err := c.Validate(); err != nil {
+		return false, err
+	}
+	if strings.TrimSpace(objectKey) == "" {
+		return false, nil
+	}
+
+	_, err := c.client.StatObject(ctx, c.bucket, objectKey, minio.StatObjectOptions{})
+	if err == nil {
+		return true, nil
+	}
+
+	responseErr := minio.ToErrorResponse(err)
+	if responseErr.StatusCode == 404 || responseErr.Code == "NoSuchKey" || responseErr.Code == "NoSuchObject" {
+		return false, nil
+	}
+
+	c.logError(ctx, "minio stat object failed",
+		zap.String("bucket", c.bucket),
+		zap.String("object_key", objectKey),
+		zap.Error(err),
+	)
+	return false, fmt.Errorf("stat minio object: %w", err)
+}
+
 func (c *minioClient) Delete(ctx context.Context, objectKey string) error {
 	if err := c.Validate(); err != nil {
 		return err