docs(agent): defer #20 KVM CI to FUTURE; keep eval-only VPS

Standing decision: IONOS Gitea/act_runner docker stays eval-tier.
vm-checks needs a separate KVM host later — not the 4G compose box.

.gitea/workflows/check.yml

@@ -86,12 +86,11 @@ jobs:
           done < <(git ls-files '*.sh')
           exit "$fail"
 
-  # ── vm-checks (DISABLED until a KVM runner exists) ────────────────────
-  # The real prize: running the checks.* VM suite + a toplevel build in
-  # CI. Needs a runner on a NixOS (or at least nix + /dev/kvm) host —
-  # register one with a dedicated label, then uncomment and set runs-on
-  # to that label. Do NOT enable this against a label that doesn't
-  # exist: Gitea queues such jobs forever instead of failing.
+  # ── vm-checks (DISABLED — FUTURE #20, not NEXT) ─────────────────────
+  # Eval-only CI is the standing decision: Gitea act_runner stays docker
+  # compose (no /dev/kvm). Full checks.* VMs need a *separate* host with
+  # nix + KVM (label nix-kvm); see agent/BACKLOG.md FUTURE #20. Do NOT
+  # uncomment until that label is online — Gitea queues forever otherwise.
   #
   # vm-checks:
   #   runs-on: nix-kvm