Wingflight Dev Build: feature/fclink

Automatic development build from feature/fclink @ 792a613

dev-build: use a valid-semver, alphanumeric-only version suffix

The dev/fclink prerelease this workflow just published used
"dev_fclink_" as its version suffix -- underscores aren't valid
semver prerelease characters. The configurator's semver comparisons
in processBoardOptions() run inside an unguarded forEach over every
release from the API; hitting one invalid version string throws and
aborts the whole loop, so this silently broke board discovery in
Development build-type mode for every release, on every branch, not
just this one.

Semver prerelease identifiers only allow [0-9A-Za-z-]; the
configurator's own filename regex (FILENAME_EXPRESSION in
firmware_flasher/util.js) only allows [0-9A-Za-z_] in this position.
The only character set satisfying both is plain alphanumeric, so
strip separators entirely for the version suffix (dev,
e.g. "devfclink074c379") instead of substituting one. The release/tag
name itself has no such constraint, so it keeps a readable hyphenated
slug (dev/fclink) -- just renamed the existing SLUG var split into
SLUG (tag) and VER_SLUG (version suffix) so both jobs stay in sync.

Rebuilt on every push to this branch -- this release is replaced, not
accumulated. Not for production use.