feat: add .env to gitignore for diffusion api v1

Added the .env file path for the diffusion API v1 to the .gitignore file to prevent sensitive environment configuration from being committed to the repository. This follows security best practices by ensuring that local development environment files are properly excluded from version control.

Author: alex-render

.gitignore

@@ -191,3 +191,4 @@ cline_mcp_settings.json
 .tmp
 .continue
 .agent
+diffusion/api/v1/.env