[AlexNegrescu26]

Why

The smoke ran omp with --no-tools and failed on any agent_start. So the two behaviors a user feels most never ran in a real omp. One is the pinned poteto-mode reminder reaching the model. The other is pstackpolicy refusing a merge. The smoke also loaded the plugin only through -e, which is not a documented install shape.

What changed

• omp-port/scripted-model.mjs is a loopback OpenAI-completions provider, copied from the verify skill in feat: add verify-pstack-omp verification skill #34 and trimmed to run in process. A tool:<name> <json> prompt makes omp issue that tool call, and every request body is kept for assertions.
• Each smoke leg runs omp in a scratch HOME with an env -i style environment and a logging gh shim first on PATH. An unpinned turn's system prompt must lack skill://poteto-mode and a pinned turn's must contain it. gh --version through bash must reach the shim. A bash gh pr merge 1 --repo pstack-verify/no-such-repo --squash must come back to the model as pstackpolicy: refused, and the shim must log no call for it.
• The same checks run twice. One leg loads with --plugin-dir and -e. The other runs omp plugin link plugins/pstack in the scratch HOME and starts omp with no -e.

Scope

• Covers the audit rows for the pin reminder, the pstackpolicy gate and the install shape. The marketplace install shape is still untested.
• No workflow change is needed. The smoke passes on the CI pin v18.12.6 and on 18.14.1. The gate.yml smoke comment (lines 49-50) lists only the old checks. The lane that owns gate.yml can extend it to name the reminder, the merge refusal and the link leg.

Tradeoffs

• The unpinned turn and the gh --version call are controls. Without them, an omp that lists skill:// URIs in every system prompt, or a bash tool that skips the shim, would make the two main checks pass without proving anything.

Blast Radius

Only the smoke job changes. It now spends about 5 seconds on two legs of four model turns each, all against loopback with no credentials.

Verification

• OMP_SMOKE_REQUIRED=1 bun omp-port/smoke-plugin.mjs passes both legs on omp 18.14.1, and on the CI pin v18.12.6 with its digest checked. With no omp on PATH it prints SKIPPED and exits 0.
• Mutation proof in a temp copy of plugins/pstack, passed as the plugin-dir argument. Dropping REMINDER from the before_agent_start return fails both legs with "the pinned turn's system prompt lacks the poteto-mode reminder". Renaming the pstackpolicy merge rule fails both legs because the model gets gh-shim: pr merge 1 ... back.
• bash omp-port/check-port.sh passes. No process with a smoke HOME and no pstack-smoke-* dir is left after the runs.