Reviewer asked us to stop over-configuring the release-binaries and
release-os-package composite actions — they're called only with
vikunja or veans, so per-project paths, artifact names, cache keys, S3
target, and version-or-unstable can all be derived inside the action
from the project name. The xgo-out-name input goes away too.
Vikunja-specific pre-build (downloading frontend_dist, generating
config.yml.sample) now happens inside the action, gated on the project
input. Callers no longer need those preamble steps.
Secrets stay as inputs — composite actions can't read \`\${{ secrets.* }}\`
directly; passing them through is the simplest workaround.
Each callsite shrinks to ~13 lines of mostly-secret pass-through plus
2-4 lines of real parameters.
ed9df9064c