Make publish scripts emit release ZIP archives

[CoreyRDean]

Non-technical summary

• publish.sh and publish.bat now produce the release ZIP archives the repo already advertises, instead of stopping at a staged release/ directory.
• This matters now because the README and release install surface already promise downloadable ZIP artifacts, so contributors should get that result directly from the publish entrypoints.
• After this change, release packaging is less ambiguous: the staged tree still exists for inspection, and the host-specific ZIP is created alongside it in release/.

Technical summary

• Added host-aware archive creation to publish.sh so Unix publish runs now emit release/blitzforge-macos-arm64.zip on macOS and preserve a consistent top-level folder inside the archive.
• Added matching archive creation to publish.bat using PowerShell Compress-Archive, keeping the existing staged release/ tree intact.
• Updated ReadMe.md so the documented publish output matches the actual staged directory plus ZIP artifact behavior.
• Verification:
  • bash -n publish.sh
  • git diff --check
  • simulated ./publish.sh packaging run against the existing built bin/ artifacts with a temporary cmake stub because this host does not currently have cmake / Homebrew installed
  • inspected release/blitzforge-macos-arm64.zip with unzip -l to confirm the expected top-level archive folder and packaged contents
• Breaking changes: none.

Additional notes

• Trade-off: I kept the existing release/ staging directory instead of replacing it, so any local workflows that inspect unpacked release contents keep working.
• Deferred follow-up: there is still no versioned or tag-driven release publishing flow here; this increment only makes the existing publish entrypoints honest and complete.
• Remaining gap to the fuller release vision: GitHub Releases publication and artifact naming/version stamping are still manual.