Description

This PR reverts the updates made in PR #2654 fix: Implement path containment to prevent traversal attacks.

The original fix aimed to patch a potential path traversal vulnerability in the download functionality. However, subsequent testing revealed that the implementation introduced unintended regressions in the following areas:

File Naming/Structure: It caused legitimate download paths to be incorrectly sanitized or blocked (e.g., when using specific relative paths or symbolic links).

This revert is necessary to restore stability and correct behavior to the download API immediately. A safer, more robust solution to address the path traversal vulnerability will be developed and implemented in a subsequent PR.x.

Impact

The impact of this revert is:

• Stability Restored: The regressions caused by the original fix are eliminated, restoring correct download behavior for existing users.
• Vulnerability Reintroduced: The original, underlying path traversal vulnerability that the branch attempted to fix is temporarily reintroduced.
• No Breaking Changes: There are no breaking changes to the public API contract.

Testing

• Tests Changed: No new tests were added in this PR. This commit simply reverts the code changes and test additions/modifications from the original fix.
• The original failing scenarios (before the path traversal fix was introduced) have been re-verified to ensure that stability is restored.
• No breaking changes are necessary.

Additional Information

This revert is an emergency measure. A higher-priority ticket has been created to implement a more thoroughly tested and less intrusive solution for path traversal protection, which will be submitted as soon as possible. We are prioritizing immediate functional correctness over the security fix in the short term.

Checklist

• Make sure to open an issue as a bug/issue before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
• Ensure the tests and linter pass
• Code coverage does not decrease
• Appropriate docs were updated
• Appropriate comments were added, particularly in complex areas or places that require background
• No new warnings or issues will be generated from this change

Fixes #2660