SMQ-2832: Fix make sed -i compatible with both macOS and Linux

[nintran52]

What type of PR is this?

This is a bug fix because it fixes the following issue: sed -i syntax incompatibility between macOS and Linux in vault environment variable setup script.

What does this do?

This PR fixes a cross-platform compatibility issue in the vault_copy_env.sh script where sed -i fails on macOS due to BSD sed syntax. The script now detects the OS and applies the correct -i option:

• sed -i '' for macOS (BSD sed)
• sed -i for Linux (GNU sed)

No functionality is broken or changed — the behavior is preserved but made portable across systems.

Which issue(s) does this PR fix/relate to?

• Related Issue Bug: sed -i behaves differently on macOS and Linux, causing script failures #2832
• Resolves #

Have you included tests for your changes?

No, I have not included tests because this is a shell script fix targeting developer tooling, which is hard to unit test. However, I manually tested on both macOS and Linux to ensure compatibility.

Did you document any new/modified feature?

No new features. Behavior remains the same. The logic is now more robust across environments.

Notes

• This fix is important for contributors and CI/CD systems that use macOS or Linux interchangeably.
• A follow-up update in README.md or CONTRIBUTING.md to remind contributors about sed portability could help avoid this in future.

[nintran52]

@dborovcanin could you take a look

[nintran52]

I fixed the comment, @dborovcanin pls help me to check