remove c0re.preBuildAgentTemplates and agentBaseToplevel

docs/scheduler/coordinator.md

@@ -515,28 +515,6 @@ For a hive-wide cap across all containers together, set
 `systemd.slices.machine.serviceConfig.CPUQuota` in your NixOS
 config — all nspawn containers live in `machine.slice`.
 
-### Pre-building agent templates
-
-`preBuildAgentTemplates` (default `false`) causes the host NixOS
-build to pre-fetch the `agent-base` container system closure, which every
-agent builds from, into `/nix/store`, instead of
-leaving that work to the first `nixos-container start`. The
-trade-off:
-
-- **On** (recommended for x86_64 hosts that care about first-spawn
-  latency): the first `nixos-container start` for any new agent
-  completes in seconds because nothing remains to fetch. Cost:
-  `preBuildAgentTemplates` adds the full nixpkgs runtime closure + claude-code + the harness
-  binary to the host system closure (low single-digit GB
-  additional).
-- **Off** (default): the host closure stays lean; the first spawn
-  does all the eval + fetch work at runtime (can take a few
-  minutes on a fresh store).
-
-**Note**: the meta flake pins the toplevel to `x86_64-linux`. Enabling on an
-`aarch64` host forces a cross-compilation or remote-builder build,
-which is almost never desired. Leave off on non-x86 hosts.
-
 ---
 
 ## See also