feat(microvm): Claude Code 2.1.276 rootfs pins, and a VM run that says what it ran

Every rootfs on the fleet had sat on Claude Code 2.1.223–2.1.226 since August
while the container tier moved to 2.1.276, and nothing recorded either. GLM
and Kimi exist only as microVM backends, so "have we upgraded GLM and Kimi"
is this change and the rebuild it drives.

Pins. All four agent-* images pin 2.1.276 — as separate ARGs, since Docker has
no include and each file has to stay reproducible alone — and
scripts/fc-build-rootfs.sh refuses to build if they disagree, naming the odd
one out. They had already drifted (claude 226, the rest 223) under comments
saying "same version on purpose". Between 2.1.226 and 2.1.276, 2.1.265 and
2.1.275 each broke every turn on ANTHROPIC_BASE_URL endpoints, which is how
glm and kimi reach `claude` inside a VM; the container-tier verification never
exercised that path, so the VM runs on those backends are the real test.

Provenance. `VmOutcome` carries the rootfs the node reported booting and the
guest's own `claude --version`; `launch_microvm_phase` persists both as
`checkpoint.vm` beside `records` (the two readers parse only `records`) and
names them in its log line. "Which image and CLI did this mission run on" is
a query now.

Independence. `evaluator` derived the implementer family from a constant
`"anthropic"`, true while every backend was Claude on Anthropic. With glm and
kimi rootfs it made a glm mission judged by glm:glm-5.3 read as
`independent = true` — the one claim that path exists to make honestly.
`implementer_family(missions.backend)` mirrors `microvm_credential_for`; the
subscription judge is now independent exactly when the agent did NOT run on
Anthropic.

Harness. `verify-mission-delivery.sh glm|kimi` run the microvm scenario on
each backend and add the proof the mission itself cannot give: the placed
node's journal must show the VM dialling that provider's host, never being
denied it, and dialling nothing else but the forge — a model's self-report is
measured worthless here. `assert_cli_version` reads checkpoint.vm. The stale
scratch-repo default (dead since the 09-14 wipe) is the re-synced id.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01WZb5A2kfVfjpdwSochkuHz

scripts/fc-build-rootfs.sh

@@ -23,6 +23,19 @@
 
 set -uo pipefail
 
+# Drift guard. The four agent-* images must pin ONE Claude Code version: a solo
+# run and a composed run's verifier should differ by provider and by nothing
+# else, and on 2026-09-18 they had already drifted (claude 2.1.226, the rest
+# 2.1.223) under comments saying "same version on purpose". Refuse to build a
+# rootfs from a set that disagrees, and say which.
+repo_root="$(cd "$(dirname "$0")/.." && pwd)"
+pins=$(grep -h '^ARG CLAUDE_CODE_VERSION=' "$repo_root"/images/agent-{claude,glm,kimi,ornith}/Dockerfile 2>/dev/null | sort -u)
+if [ "$(printf '%s\n' "$pins" | grep -c .)" -ne 1 ]; then
+  echo "fc-build-rootfs: the agent-* images pin different Claude Code versions — fix that first:" >&2
+  grep -H '^ARG CLAUDE_CODE_VERSION=' "$repo_root"/images/agent-{claude,glm,kimi,ornith}/Dockerfile >&2
+  exit 2
+fi
+
 WORK="${FC_WORK:-/opt/clawmates-fc}"
 FAILURES=0
 pass() { printf 'PASS  %s\n' "$*"; }