Session 59: Addendum + work-order 1.6 + Phase 2 + Phase 3 (2352 tests)

Overnight sprint for the Saturday 10 AM ET deploy gate — day one of the
public ledger record locks against freshly posted lines.

Task A — ledger team/opponent (migration 020, applied at 0 rows):
  populated in both write paths from the real feed; opponent only when the
  player's team matches a game participant (never guessed). Roadmap: Phase
  4.5 WNBA ESPN-boxscore settlement (due ~Jul 24) + Phase 5 per-tier
  calibration logged.

Task B — work-order 1.6 CLOSED (canonical player keys):
  - searchPlayer resolves via nameKey; the old matcher deleted accents
    ("Sanchez" with acute -> "snchez") and substring-guessed onto the WRONG
    player (the mismatched last-10 bug). Ambiguous -> null, never guess.
  - Slate JOIN INVARIANT: a graded prop whose player's real team isn't in
    the game is dropped (TB player can't render under MIL@PIT) — locked by
    tests that fail the suite on regression.
  - grades:{sport} TTL 2h -> 6h (expired between 5h cron gaps — the real
    cause of /team "No active props" for slate players).

Task C — Phase 2 slate UX: tabs are THE filter (URL ?sport=, deep-linkable,
  duplicate legacy tablist removed); cards cap at 6 graded props sorted
  A+->F with ALL N READS in-place expander; waiting states show the real
  next pipeline run ("Grades post ~6:00 PM ET").

Task D — Phase 3 mobile P0: root cause of vanished 390px nav was HIDE_ON
  including '/' (landing had zero navigation) — fixed; html/body overflow-x
  contained; GAME LINES collapses to best-line summary + "N BOOKS" expander
  below 640px; venue drops before time/pitchers ever truncate.

Live verification: raw ESPN today STILL returns the Jun 13 NYK@SA Finals
game without a date pin; the pinned fetch returns 0 games, 0 off-date.

Backend 2327 -> 2352 tests (202 suites), web build exit 0.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

web/src/lib/slateAdapter.js

@@ -241,14 +241,37 @@ function gradedAgo(iso, now = Date.now()) {
   return `${Math.round(hrs / 24)}d ago`;
 }
 
+/** Team-identity match by nickname token (last word) — "New York Yankees"
+ *  ↔ "Yankees"; exact string match also accepted. */
+function slateTeamsMatch(a, b) {
+  if (!a || !b) return false;
+  const sa = String(a).toLowerCase(), sb = String(b).toLowerCase();
+  if (sa === sb) return true;
+  return teamMascot(a) !== '' && teamMascot(a) === teamMascot(b);
+}
+
 /**
  * Build pre-graded `playerStrips` for one game by OVERLAYING the snapshot's
  * locked grades onto the game's odds-derived props (which already carry the
  * correct game grouping). Each prop is either graded (grade + gradedAt + delta)
  * or `awaiting:true` (no snapshot match yet → "Awaiting next scan", no Read
  * button). Archetype comes from the snapshot's per-player classification.
+ *
+ * Session 59 (work-order 1.6) — THE JOIN INVARIANT: when the snapshot knows
+ * the player's REAL team (grades carry `team` from the stats resolve) and
+ * the caller passes the game's participants (`gameTeams`), a prop whose
+ * player does NOT belong to either team is DROPPED from the card entirely —
+ * a bad feed row must not render a TB player under MIL@PIT. Props without
+ * team info are kept (can't verify ≠ wrong).
  */
-function buildPlayerStripsFromProps(gameProps, gradeIndex, deltaIndex, now = Date.now()) {
+/**
+ * @param {Array<object>} gameProps
+ * @param {Record<string, any>} gradeIndex
+ * @param {Record<string, any>} deltaIndex
+ * @param {number} [now]
+ * @param {{home?: string, away?: string} | null} [gameTeams]
+ */
+function buildPlayerStripsFromProps(gameProps, gradeIndex, deltaIndex, now = Date.now(), gameTeams = null) {
   const byPlayer = {};
   const order = [];
   for (const p of gameProps || []) {
@@ -257,10 +280,16 @@ function buildPlayerStripsFromProps(gameProps, gradeIndex, deltaIndex, now = Dat
     // / "AJ Ewing") merge into ONE strip; display the longest seen variant.
     const pk = nameKey(p.player);
     const rec = gradeIndex[gradeKey(p.player, p.stat_type || p.stat)];
+    // Join guard: known player team that isn't in this game → bad row, drop.
+    const knownTeam = (rec && rec.team) || p.team || '';
+    if (knownTeam && gameTeams && (gameTeams.home || gameTeams.away)) {
+      const inGame = slateTeamsMatch(knownTeam, gameTeams.home) || slateTeamsMatch(knownTeam, gameTeams.away);
+      if (!inGame) continue;
+    }
     if (!byPlayer[pk]) {
       byPlayer[pk] = {
         player: displayName(p.player),
-        team: p.team || '',
+        team: knownTeam,
         archetype: rec && rec.archetype ? { primary: rec.archetype } : undefined,
         stats: [],
         props: [],