feat(thressgame-coverage): Wave 19 (close 6 production gaps, lift all fixmes)

T85: Wired Wave 12 move-gen attrs into engine.ts:getAllLegalMoves (the path the drag UI actually uses):
- BlockAllExceptKing (game-level early-return)
- BlockedPieceTypes (game-level early-return)
- MovesAs (per-piece substitution via lookupMoveGenerator)
- MovesAlsoAs (additive; deduped via dedupeMoves helper)
- MoveClassRestriction (post-filter on the entire move set)

Previously these attrs only filtered rules/turn.ts:getLegalMovesForPiece, but the production drag path goes through engine.ts. Now both paths apply identical filters.

T86: engine.ts:applyMove now honors isPawnPush:
- pushedPieceId moved to pushedTo (defender shoved forward)
- pawn moves to diagonal target square (no capture retract)
- HasMoved set on pawn
- Hook firing + turn advancement preserved

5 fixmes lifted in move-gen-attrs.spec.ts (MovesAs, MovesAlsoAs, BlockedPieceTypes, MoveClassRestriction, PawnPushesPiecesEnabled).
1 fixme lifted in orphan-primitives.spec.ts (must-class consumer now active).

E2E status: 30/30 thressgame-coverage tests PASS. 0 fixmes. 0 skips.
Unit tests: 2866 -> 2868 (+2 from new applyMove unit tests). bun run check exit 0.

packages/chess/e2e/orphan-primitives.spec.ts

@@ -1465,7 +1465,7 @@ test('W18/spawn-marker-pair: portal-end pair at a1 ↔ h8 with mutual MarkerLink
 // REJECTED — the test would then assert an attempted e2-e4 leaves
 // the pawn on e2.
 
-test.fixme(
+test(
   'W18/must-class: capture restriction prevents non-capture moves (consumer deferred)',
   async ({ browser }) => {
     const ctx = await browser.newContext();