Wave 5B: Pitcher Arsenal via Baseball Savant (Statcast)

D4 — build the FREE Baseball Savant adapter for pitch-level identity
(mix / velo / usage% / whiff%), the missing layer statsapi doesn't carry.

- savantAdapter.getPitcherArsenal(id|name) — normalizes two public Savant
  CSV leaderboards (csv=true, NO parsing dependency): pitch-arsenal-stats
  (usage% + whiff% + K%) + pitch-arsenals avg_speed (velo). League-wide,
  cached 24h + in-memory mirror, indexed by MLBAM id. Defensive: null on any
  unrecognized shape; a missing velo/whiff is ABSENT (null), never 0.
  Injectable (fetchImpl/statsCsv/veloCsv/resolveId) → tests hit no network.
  Live endpoints VERIFIED (200, exact columns) from the sandbox.
- GET /api/stats/pitcher/:name/arsenal (stats.js) + Next proxy. MLB-only;
  an error/miss returns { found:false } so the card self-hides honestly.
- PitcherArsenal.tsx (+ barrel) — the mockup's PITCHER IDENTITY strip:
  pitch mix % + velo + whiff%, mono/tabular, ranked by usage, sharpest-whiff
  pitch highlighted green. Self-hides (heading included) when arsenal absent.
  Mounted on the MLB player profile (a pitcher surface). Context, not a
  graded market value.
- Tests: savantAdapter (fake CSV → ranked arsenal; unknown shape/blank cells
  → absent not 0; name→id resolve) + PitcherArsenal source locks (self-hide,
  mono/tabular, em-dash-not-zero). +2 suites / +17 tests (3012 → 3029).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/app/globals.css

@@ -1333,6 +1333,9 @@ html[data-font="readable"] .wm::after { opacity: 0.45 !important; }
 /* Terminal's multi-column grid stacks on mobile. */
 @media (max-width: 768px) {
   .terminal-grid { grid-template-columns: 1fr !important; }
+  /* Pitcher-identity (Wave 5B): identity + arsenal columns stack; the arsenal
+     table keeps its own internal grid. */
+  .parsenal-grid { grid-template-columns: 1fr !important; }
 }
 
 /* ── Session 59 (work-order 3.2) — overflow containment at 390px ──────── */