Ledger takeable tagging (deferred C2); efficiency challenger BLOCKED

Champion grade UNCHANGED. Push scoring untouched. Additive tags only — nothing
deleted, nothing re-settled.

PART A — THE EFFICIENCY CHALLENGER: BLOCKED, NOT BUILT.
Review Zero came back ABSENT on all three inputs:
  0.1 efficiency scores DO NOT EXIST (zero occurrences of market_efficiency /
      marketEfficiency / efficiency_score in src/ or web/src/).
  0.2 base thresholds DO NOT EXIST (engine1.js has zero `edge` references — the
      grade is not an edge-vs-threshold comparison; grade_thresholds.json holds
      PROBABILITY bands).
  0.3 the +/-0.05 additive efficiency nudge DOES NOT EXIST. The only 0.05s on
      the grade path are featureCache.teammate_absence_bump, a bvp_advantage
      cutoff, and p*0.9+0.05 inside probabilityEstimator (the 0.5*0.1 term of
      the shrink-toward-0.5). There is no additive scaling to replace.

So a challenger differing from the champion in EXACTLY ONE thing cannot be
constructed: there is no additive scaling to swap, no base threshold to
multiply, and engine1.js has zero `sport` references so market cannot reach the
grade. A threshold must exist first — that is R1 of
specs/full-output-grade-mapping.md, an explicitly held separate order. Shipping
R1+R4 together would make the Phase-3 delta report misleading: the re-letter
would be driven mostly by switching to probability grading while being
presented as the efficiency fix.

0.4 coverage: the spec names 5 scores; the live ledger has 11 markets and only
MLB total_bases maps to one. 9 of 11 have no score, so "all scored markets"
cannot be satisfied without inventing 9 numbers.

PART B — LEDGER TAKEABLE TAGGING: BUILT (the deferred C2).
New src/config/takeableStandard.js: floor on the minus side, UNCAPPED plus.
Deliberately NOT valueEngine.isTakeable (the -160..+200 PROMOTION band) — a
+400 prop is not promotable but IS takeable; a test asserts the two diverge on
the plus side and agree at the floor so they can never quietly merge. Absent
price returns null, never false (Number(null) === 0 would tag a missing price
takeable). The floor is POLICY not derived (C1 could not derive one) and is
labelled so; each row records takeable_floor so a re-derivation can re-tag.

Migration 034 (applied + tracked): ledger_entries.takeable boolean +
takeable_floor numeric, nullable, partial index. Forward tagging in
ledgerService at row build; backfill in one statement.
Result: 1254 rows, 1246 tagged (781 takeable / 465 below floor), 8 NULL with
null_despite_price = 0 (the NULLs are genuinely priceless rows). Settled 1163
and graded 1254 unchanged.

PART C — the model-version boundary tag is DELIBERATELY NOT APPLIED: no scaling
change shipped, so no boundary exists, and stamping one would mark a model
transition that never happened. modelEras.js is its home when a real one lands.

Floor: 312 suites / 3890 tests green (8 new), web build exit 0.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QJs13VsyiSKYQP6rj3NNmc

src/services/ledgerService.js

@@ -29,6 +29,10 @@
 
 const { nameKey, normalizeName } = require('../utils/playerName');
 const { settleResult, statValue, logRowOnDate } = require('./outcomeService');
+// The LEDGER takeable standard (floor on the minus side, UNCAPPED plus) — a
+// DIFFERENT question from valueEngine's -160..+200 promotion band. See
+// config/takeableStandard.js for why the two must not be merged.
+const { LEDGER_TAKEABLE_FLOOR, isLedgerTakeable: takeableFor } = require('../config/takeableStandard');
 
 const CONFLICT = 'user_id,player_key,stat,line,side,game_id';
 const UPSERT_CHUNK = 200;
@@ -236,6 +240,16 @@ function rowsFromSnapshot(sport, grades, oddsProps, nowIso) {
       line,
       side,
       locked_odds: locked.odds != null ? String(locked.odds) : oddsForSide(prop, side),
+      // TAKEABLE TAG (2026-07-31, specs/takeable-tagging.md) — was this a price a
+      // bettor could actually have taken? FLOOR on the minus side, UNCAPPED plus.
+      // 🔴 NOT `valueEngine.isTakeable` (the -160..+200 PROMOTION band the hero and
+      // board rank on): a +400 prop is NOT promotable but IS takeable. Keep separate.
+      // The floor is POLICY, not derived (C1 could not derive one — every price
+      // bucket's ROI interval contained zero), so each row records the floor it was
+      // tagged under and a re-derivation can re-tag safely. Absent price → NULL, an
+      // honest absence, never false.
+      takeable: takeableFor(locked.odds != null ? locked.odds : oddsForSide(prop, side)),
+      takeable_floor: LEDGER_TAKEABLE_FLOOR,
       book: (prop && prop.book) || g.book || null,
       grade: g.grade,
       edge: numOrNull(g.edge_pct),