ci: flag pre-release tags so they don't become "latest" (#13 prep)

The release workflow uses softprops/action-gh-release without setting
prerelease. Tags like v0.5.1-rc1 would get published as full releases,
and GitHub's /releases/latest endpoint could return them.

install.sh and install.ps1 both call /releases/latest to discover the
current version when the user has not pinned VERSION. If an rc were
marked latest, every user running the install one-liner would get
pulled onto an rc without asking.

Auto-flag anything with -rc, -beta, or -alpha in the tag name as
prerelease. Clean semver tags (v0.5.1, v1.0.0) continue to publish
as full releases exactly as before.

Author: DAB-LABS

.github/workflows/release.yml

@@ -77,6 +77,12 @@ jobs:
         uses: softprops/action-gh-release@v2
         with:
           name: SMART Sniffer v${{ steps.version.outputs.VERSION }}
+          # Auto-flag any tag with -rc, -beta, or -alpha as a pre-release
+          # so GitHub's "latest release" endpoint skips it. install.sh and
+          # install.ps1 both call that endpoint for version discovery; if
+          # an rc were marked latest, every user running the install one-
+          # liner without pinning VERSION would be pulled onto an rc.
+          prerelease: ${{ contains(github.ref_name, '-rc') || contains(github.ref_name, '-beta') || contains(github.ref_name, '-alpha') }}
           body: |
             ${{ steps.changelog.outputs.NOTES }}