Release: automate Homebrew tap and Scoop bucket updates

[MelbourneDeveloper]

[DIST-PATH-INSTALL] in docs/specs/DISTRIBUTION-SPEC.md tells users to install with:

• brew install nimblesite/tap/sharplsp
• scoop install nimblesite/sharplsp

Nothing in release.yml pushes to Nimblesite/homebrew-tap or Nimblesite/scoop-bucket, so those commands only work for whatever version someone last updated by hand. docs/plans/DISTRIBUTION-PLAN.md had this ticked as done; it has been corrected to [ ] NOT BUILT.

The blocker is now gone: every release publishes per-platform standalone server archives (sharplsp-<platform>.tar.gz / .zip) plus a SHA256SUMS covering them, which is exactly what a formula and a manifest need.

Remaining work:

• Create/confirm the Nimblesite/homebrew-tap and Nimblesite/scoop-bucket repos
• Provision a token (or GitHub App) with write access to both, scoped to the release environment alongside the existing publish secrets ([DIST-SECRETS])
• Add a publish-packages job to release.yml, needing release, that rewrites the formula/manifest URL + sha256 from the release assets and pushes
• Skip the push for prerelease (hyphenated) tags, matching how publish-marketplace handles --pre-release
• Update [DIST-PATH-INSTALL] to drop the "Not yet automated" note once it lands