Plan: Release Horizon Aid 1.0.0-rc1

Release notes snippet

• Release candidate. This release carries no functional change over 1.0.0-beta1. It is a maturity step on the way to 1.0.0 stable, so that the Horizon Aid site template recipe works with Drupal CMS by default, on stable releases.
• Today drupal/horizonaid:~1 resolves only after minimum-stability is loosened to dev, because every published version is still a pre-release. The version constraint is not the blocker: ~1 normalizes to >=1.0.0.0-dev <2.0.0.0, so a pre-release does satisfy the range once the stability setting permits it. Once 1.0.0 stable exists, composer require drupal/horizonaid works against a stock drupal/cms root with its default minimum-stability: stable and no extra configuration.
• Re-pin every cross-dependency to a published constraint after the Back to DEV change: the sixteen varbase_*_base recipes at the floors verified for 1.0.0-beta1, and drupal/vartheme_bs5_horizonaid at ~1.0.0-rc1.
• Verified by two fresh browser installs of the released tag, one on a plain Drupal CMS base and one on a drupal/varbase_project base. Both green with no rescue cache rebuild: every path 200, 70 nodes, 8 Canvas pages, 74 media, 25 taxonomy terms, 248 enabled extensions, home page 21 images with 0 broken and 0 console errors, and zero PHP watchdog rows.