design: TDDs 0064–0065 + ADR 0014 (model capability by job)

[cahenesy]

Design

PRD-rev 5dbf968 (PR #178). Two draft TDDs + one ADR.

• TDD 0064 (supersedes 0057) — judgment-worker defaults and cheaper-pin warning (NFR-3, FR-87, FR-52, FR-10/15/50). review= equals build= when unset. Design-reviewer model: inherit. FR-87 parent warning uses “differs from,” not “below.”
• TDD 0065 — FR-86 parent-session check. Observe the harness session artifact; fetch official models docs this turn; warn+ask if weaker or unreadable. No static rank map.
• ADR 0014 — accepted; supersedes 0009. Revises ADR 0010’s “different-model artifact” consequence without editing 0010’s body.

Do not merge until you have reviewed the design. Merge is the design gate that makes these TDDs buildable (/build-tdds).

Design-critique verdict

Independent design-reviewer (fresh worker): DESIGN_REVIEW: PASS.

Rubric: co-created with the user (## Evaluation rubric identical in both TDDs). Gate graded against that table. No failing row. 0064 high-quality on traceability, interfaces, verification, scope, naming, no-rank-map; alternatives acceptable (the HQ live-fetch pair lives in 0065). 0065 high-quality on alternatives / no-rank-map / verification; interface concreteness acceptable (page-grounded judge is not mechanical).

Findings (none blocking; folded where cheap before this PR):

• minor — Grok observe cwd: use $PWD first, git-root fallback (folded).
• minor — skip Claude <synthetic> as message.model (folded).
• minor — FR-87 verb “differs from” not “is below” (folded).
• nit — Claude slug maps . → -; Grok encode example %2F… (folded).
• nit — README different-model sweep deferred (named in 0064). Implement skill ADR cite retargeted 0009 → 0014 (in 0064 scope).

Open assumptions & waivers

• session-model observation — resolved: session artifact (Grok summary.json current_model_id; Claude jsonl last non-synthetic message.model). Missing env/file/field = unreadable → warn+ask.
• weaker/newer comparator — resolved: no static rank map. Compare is a this-turn official-docs fetch. Recency-only is forbidden. Fetch/judge fail is unreadable → warn+ask.
• live catalog source and ranking — resolved: fetch Anthropic models overview + Claude Code model-config, or xAI models/flagship. Bar is live vendor top-tier and may be newer than the models.sh binding.
• lookup failure / no key / offline — resolved: cannot fetch or cannot judge → unreadable → warn+ask. Evals do not hit the network.
• design-reviewer frontmatter pin — resolved: inherit; no model: sonnet. Independence is a fresh worker.
• FR-87 warning visibility — resolved: parent prints THROUGHLINE_*_MODEL=<id> differs from the most-capable default; continuing. Mechanical verify pin does not warn.
• one binding site — resolved: models.sh is the only dispatch binding. FR-86 does not copy ids.
• ADR 0009 conflict — resolved: ADR 0014 supersedes 0009.