FreqTrace v0.4.1

Signed with an Apple Development certificate (not notarized). Opens cleanly on Macs that trust this developer; generally blocked on others.
On an unrecognized Mac, first launch: right-click FreqTrace.app > Open > Open.

What's Changed

• Lower deployment target to real floor + v0.4.1 by @vk0eppel in #58
• Fix Release optimizer crash exposed by macOS 15 target by @vk0eppel in #59

Full Changelog: v0.4.0...v0.4.1