model-routinglisted

# Model Routing ## 0. Ledger pre-check — posterior beats prior Before scoring anything, read `.claude/routing-ledger.md`, in this order: - Class has a live **repo-playbook** entry (not quarantined, floor not reached) → dispatch one tier below the entry's provenance as a PROBE, entry quoted in the brief (`tier-decay` §3). **A live entry outranks PRIORS** — this is what keeps decay iterating. - Else task matches a class in **PRIORS** (≥3 logged rows) → use its empirical default tier, skip the rubric. - Otherwise → score below. The rubric is only the cold-start prior. ## 1. Scoring rubric Score the task on four axes; sum the points. | Axis | 0 | 1 | 2 | 3 | |-----------------|-----------------|------------------|--------------------------------|----------------------------| | Spec ambiguity | fully specified | minor gaps | requires design decisions | — | | Reasoning depth | mechanical | standard logic | multi-constraint / algorithmic | novel algorithm, proof-like| | Blast radius | 1 file | 2–5 files | >5 files or shared/core module | — | | Risk surface | cosmetic | user-visible bug | data / perf / concurrency | security, money, irreversible | Route: - **0–3 → [T1]** `executor` (Sonnet 4.6) - **4–6 → [T2]** `heavy-executor` (Opus 4.8) - **≥7, or any axis at its maximum → [