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.

issue に示されている AWS_S3_BUCKET_PREFIX と ENVIRONMENT に基づくバケット構成を backend で検索し、バケット設定が読み取られる箇所を追跡してください。その合成を単一の設定可能なバケット名設定に置き換え、設定された名前が変更されずに使用されることを検証してください。環境サフィックスのない名前も含みます。