tier-decaylisted

# Tier Decay — amortize reasoning Goal: every problem CLASS is solved at a high tier **at most once**. Afterwards it exists as a documented pattern executable one tier lower. Expensive tokens are capital expenditure; this protocol is the amortization schedule. The routing rubric is only the cold-start prior — the ledger is the posterior. ## 1. Ledger — one row per task, every tier Append to the LOG table in `.claude/routing-ledger.md`: `| date | class | predicted | executed | outcome | escalations | playbook |` **Class signature**: 2–4 hyphenated tokens, `<verb>-<object>-<surface>` (e.g. `add-endpoint-rest`, `write-migration-postgres`, `fix-flaky-test-jest`). Before minting a new class, scan the LOG and reuse an existing signature — matching power depends on signature discipline. When a class reaches **≥3 rows**, compute/update its row in the PRIORS table: its empirical default tier now OVERRIDES the scoring rubric. ## 2. Distill — after [T2]/[T3] success only Distill iff the class will plausibly recur (expected ≥2 future occurrences). Write a **≤15-line** entry into the `repo-playbook` skill, following its format. Distill the DECISIONS — invariants, order of operations, the trap and its avoidance — never diffs, never secrets, never volatile business values. A wrong pattern costs more than no pattern: when in doubt, don't distill. ## 3. Probe — the downgrade test On the NEXT occurrence of a distilled class, dispatch **one tier below the entry's provenance tier**, wi