Make AWS S3 bucket name fully configurable

Describe the issue
Currently, the AWS S3 bucket name is constructed dynamically in code like this:

return f"{self.AWS_S3_BUCKET_PREFIX}-{self.ENVIRONMENT}"

• This assumes that all bucket names will follow the - pattern.

• However, in future scenarios, users or organizations might bring their own bucket names, which may not include the environment in their naming convention or may follow completely different patterns.

• Hardcoding the bucket name composition like this makes it inflexible and prone to failure if the naming convention does not match.

Expected behavior

• There should be a single, fully-configurable AWS S3 bucket name setting(e.g., AWS_S3_BUCKET_NAME)which is used directly without concatenating prefix and environment in code.

• This allows using existing customer buckets regardless of naming convention.

Busca en el backend la construcción del bucket basada en AWS_S3_BUCKET_PREFIX y ENVIRONMENT que se muestra en el issue, y sigue el flujo hasta donde se lee la configuración del bucket. Sustituye esa composición por una única configuración del nombre del bucket y verifica que el nombre configurado se use sin modificaciones, incluidos los nombres sin un sufijo de entorno.