Rename blob containers with _del suffix on soft delete to restrict file access

[magicxor]

Currently, when a post or thread is soft-deleted, the associated blob container retains its original name. This means files remain accessible via direct public links even if the content is hidden in the application.

We need to implement a mechanism to rename the blob storage container by appending a _del suffix immediately upon soft deletion. This will invalidate existing public URLs. Additionally, we need to update the file serving logic to allow access to *_del containers only for users with Moderator or Admin roles.