smoke: mock admin @all + Writer compact-in-place both red on main #917

Context

core/dev/check.sh --only smoke (mock LLM + DSH) fails 2 assertions on both main and #908 / issue/903-step0-default-harness. Confirmed not a #903/#908 regression (same fails at main tip 32f3e7c with same DSH build).

Observed on hk2 (infermatrix-hk2-hsliu) with DSH dsh-v0.2.0-rc.2, pnpm 11.7, built system.node. Shots: check-20261024-0230 (#903) and main worktree re-run.

Failures

1. admin calls everyone — expect Chief to @all / answer everyone; got only 1 answer (我觉得可以。). Hypothesis: mock-llm admin detection uses a Members: … and you (admin). style regex that no longer matches the current group prompt → steward/Chief path never treats the caller as admin.
2. Writer condensed in place — steward returns compact ×3 but part count still +3. Hypothesis: compact not applied in-place / still switches part; check parts.js / DSH compact path vs smoke expectation (CONTEXT_WINDOW=100000 CHECK_RATIO=0.45).

Out of scope

• Do not change Step 0: default harness + usage five fields (#903) #908 Step 0 (default harness + usage five fields).
• Live DSH / DEEPSEEK_API_KEY / control-set are separate.

Acceptance

• Fix mock admin detection (or prompt wording) so “admin calls everyone” passes under mock smoke.
• Fix or correctly assert Writer compact-in-place so that case passes (investigate before changing product behavior).
• core/dev/check.sh --only smoke green on the fix branch (mock; no API key).
• Note any remaining DSH-side follow-ups if compact is upstream.

Related

• Draft PR Step 0: default harness + usage five fields (#903) #908 (Option B Step 0) — leave alone.
• Room Step 0: extract default harness + usage five fields (#874 B) #903 / Review acceptance item on mock smoke.