fix(utils): remove redundant comment in vix_utilsConfig.cmake

Clean up vix_utilsConfig.cmake.in by removing an unnecessary comment.
No functional changes.

fix(utils): prefer header-only fmt and spdlog targets

fix(utils): make fmt a direct PUBLIC dependency and remove conditiona…

…l spdlog fmt handling

fix(utils): use fmt/ostream instead of spdlog/fmt/ostr.h for compatib…

…ility across platforms

fix(utils): clean CMake configuration and fix linking issues

fix(banner): add spacing between label and value in runtime logs

- insert missing space in row() rendering
- fix 'Threads:8/8' → 'Threads: 8/8'
- improve readability of runtime banner output
- ensure consistent formatting across all rows

fix(utils): handle warning flags in header-only mode