1.8.12 — Fix Windows Tentacle upgrade download (resolve $RID in the URL) upgrade-windows-tentacle.ps1 left $RID unexpanded in the single-quoted download URL, 404ing every Windows self-upgrade since the feature shipped. Resolve it before download (#418), plus cross-OS coverage for the gaps that hid it (agent-resolved==builder, no-placeholder invariant, release-workflow contract, mirror 404s unresolved tokens).