### Summary

The files retrieve, content, and delete endpoints enforce LiteLLM API-key authentication but do not enforce tenant ownership for raw provider file IDs. Managed unified IDs go through the managed-file hook, while any other provider file ID is forwarded to the provider using the current team's or shared provider credentials

### Current behavior

In `litellm/proxy/openai_files_endpoints/files_endpoints.py`:

- Unified managed IDs are routed through `ManagedFileRepository` and the managed-file hook - Raw cloud-storage URIs are rejected - Other raw IDs take the fallback branch, call `apply_team_provider_credentials()`, and invoke `litellm.afile_retrieve()`, `litellm.afile_content()`, or `litellm.afile_delete()` - `validate_managed_files_requirement()` is currently used on the upload path and does not make retrieve, content, or delete reject raw provider IDs

If multiple tenants use the same provider account, knowledge of another tenant's provider file ID is enough to make the proxy ask the provider for that object under shared credentials. The provider may authorize the operation because it sees the shared account, not the LiteLLM tenant

### Reproduction

Use two LiteLLM …