tools image: code (vscode) is absent, so the real-lifecycle ratchet regressed 28 to 27

[SYKhayyat]

Classification: test-infrastructure problem (image build / probe). The Dockerfile claims a backend it does not install, and the ratchet — correctly — refuses a plan-smoke in place of a real lifecycle.

The problem

The tools image fails the real-lifecycle ratchet:

FAIL  real-lifecycle ratchet: 27, and container-linux-tools-local has done 28 before.
        Something stopped running. A plan-smoke satisfies the audit above, so this
        is the only check that notices coverage collapsing rather than breaking.
        did a real lifecycle here: apt asdf bun cabal cargo conda dotnet emacs gem github
        go helm krew link luarocks mise mix nimble nix npm opam pipx pixi pub service spack uv
        the image says these are ABSENT: code
        A manager the image failed to install cannot have a lifecycle. If one of these was here
        last run, that is the whole shortfall — fix the install in the Dockerfile rather than
        the number in /src/scripts/lifecycle-floor.txt.

Root cause

Dockerfile.tools:194 claims code (the vscode backend's binary) as part of the image's shipped set — the probe loop for m in nix code flatpak stack ... — but no step installs vscode/code-server. In the built image command -v code fails and /etc/shall-image-managers records code ABSENT. The vscode backend therefore cannot complete a real install→list→remove lifecycle, and the leg measures 27 against a recorded floor of 28. The coverage audit reports the absence as a soft, but the ratchet — which cannot be satisfied by a plan-smoke — goes red.

The ratchet comment (scripts/lifecycle-floor.txt) says the floor is 28 and was raised deliberately ("Raised 26 -> 28 on 2026-08-21 ... the repaired image measures 28"); the floor is not the thing to edit. The image is: install the binary it claims, or stop claiming it in the probe.

Fix

Install vscode/code-server in Dockerfile.tools (so the code probe finds it and the backend gets a real lifecycle), or remove code from the probe list so the image stops claiming a backend it does not ship. Either way the count and the floor must then agree without lowering the floor.

Evidence

• linux_run.txt:9665–9682, 9690–9695.
• Reproduced against shall-it-tools: /etc/shall-image-managers contains code ABSENT, command -v code fails.
• Dockerfile.tools:194–198 (the probe that names code).

[SYKhayyat]

Root-cause breakdown of #25 for the tools image (code absent / ratchet regression).

[SYKhayyat]

Fixed in 7c0560c. The real 28th lifecycle was composer, not code: with composer's lifecycle broken by the empty-output parser bug, it never completed and the count dropped to 27. Fixing composer restored the count and the ratchet passes. Also installed Hex at build time so mix is not degraded from the first health check. Verified: tools leg green (463 passes, 0 failures).