Add MarkSeen Functionality to Notification System

- Implemented the MarkSeen method in the notification client to mark notifications as seen, enhancing user interaction with notifications.
- Added MarkSeenRequest and MarkSeenResponse structs to facilitate the request and response handling for marking notifications.
- Updated the NotificationService interface to include the new MarkSeen method, ensuring consistency across the service layer.
- Enhanced the SDK with a QuickMarkSeen convenience method for easier usage in client applications.
- Included logging for successful and failed attempts to mark notifications as seen, improving traceability and debugging capabilities.

pkg/notification/client.go

@@ -304,6 +304,65 @@ func (c *Client) buildQueryParams(req *GetNotificationsRequest) string {
 	return result
 }
 
+// MarkSeen marks a notification as seen
+func (c *Client) MarkSeen(ctx context.Context, notificationID string) (*MarkSeenResponse, error) {
+	if c.config.EnableLogging && c.logger != nil {
+		c.logger.Debug("Marking notification as seen", map[string]interface{}{
+			"notification_id": notificationID,
+			"base_url":        c.config.BaseURL,
+		})
+	}
+
+	// Create HTTP request
+	url := fmt.Sprintf("%s/api/v1/notifications/%s/seen", c.config.BaseURL, notificationID)
+	httpReq, err := http.NewRequestWithContext(ctx, "PUT", url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create HTTP request: %w", err)
+	}
+
+	// Set headers
+	httpReq.Header.Set("Content-Type", "application/json")
+	httpReq.Header.Set("User-Agent", c.config.UserAgent)
+
+	// Send request
+	resp, err := c.httpClient.Do(httpReq)
+	if err != nil {
+		return nil, fmt.Errorf("HTTP request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	// Read response body
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response body: %w", err)
+	}
+
+	// Handle non-2xx status codes
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		// Try to parse error response
+		var errorResp NotificationErrorResponse
+		if json.Unmarshal(body, &errorResp) == nil && errorResp.Error != "" {
+			return nil, MapHTTPError(resp.StatusCode, errorResp.Error)
+		}
+		return nil, MapHTTPError(resp.StatusCode, string(body))
+	}
+
+	// Parse success response
+	var markSeenResp MarkSeenResponse
+	if err := json.Unmarshal(body, &markSeenResp); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal response: %w", err)
+	}
+
+	if c.config.EnableLogging && c.logger != nil {
+		c.logger.Info("Notification marked as seen successfully", map[string]interface{}{
+			"notification_id": notificationID,
+			"status":          markSeenResp.Status,
+		})
+	}
+
+	return &markSeenResp, nil
+}
+
 // shouldRetry determines if a request should be retried based on the error
 func (c *Client) shouldRetry(err error) bool {
 	switch e := err.(type) {