builtbykev
888d103f95
The #1 board item — three grading bugs the phone audit surfaced, all in the live Node grade path (engine1 + analyzeViaEngine1), fixed at the source. 1. PROJECTION=0 NOW REFUSES. projectionFor returned l5_avg even when it was 0 (finite, so the `== null` gate passed it) — 9/25 live grades graded on a zero projection, producing a degenerate edge and a hollow grade. Now a non-positive reference is not a projection: projectionFor skips it and falls through to the next POSITIVE reference (l5 -> l20 -> per_90 -> xg); when none is positive it returns null and the read REFUSES (insufficient_data). The gate also gained an explicit `> 0` guard so the invariant is structural — a grade can never be emitted with a non-positive projection. Fewer graded props, honest. 2. EDGE_PCT. The formula was already (model - line) / line signed by direction — Kev's intended semantics. The broken {20,60,100,140} cluster was the proj=0 degeneracy ((line - 0)/line = 100%); with #1 those refuse, so the fabricated 100s vanish and real edges flow. The main-line edge now reuses the VALIDATED projection (edgePctFor accepts an optional ref) so edge and the persisted projection can never diverge. Frontend |edge|>40 guard stays as a safety net. 3. LETTER == THRESHOLD_TABLE(CONFIDENCE). engine1's hand-rolled GRADE_TO_CONFIDENCE drifted a full sub-tier low (B -> 0.55, which the canonical grade_thresholds.json calls B-) — the "B at 45%" the audit caught. Now confidence is DERIVED from each grade's band MIDPOINT in grade_thresholds.json (one source of truth, shared with the Python engine), so applying the threshold table to any grade's displayed confidence resolves back to the same letter. Proven for all 11 grades. Regression locks: tests/unit/mlbGradeDegradation.test.js (14 tests). Backend suite 269/3253 green, web build exit 0. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>