chore: resolve stash merge conflicts + stage sliding.ts range-bonus changes

packages/chess/src/rules/sliding.ts

@@ -9,6 +9,12 @@
  *   2. Ally-occupied       → stop immediately (square NOT included)
  *   3. Enemy-occupied      → legal capture, then stop
  *
+ * RangeBonus fact (seeded by the range-bonus modifier descriptor) extends
+ * or limits how many squares a piece may travel per ray. The effective
+ * maxSteps is clamped to [0, 7] — the natural board-geometry ceiling on
+ * an 8×8 board. For standard chess (full range), RangeBonus=0 is the
+ * default and behaviour is identical to the original implementation.
+ *
  * Intentionally NOT handled here (see later phases):
  *   - check filtering  → P2.18
  *   - turn order       → P2.13
@@ -28,9 +34,22 @@ import {
 } from "./board-queries.js";
 import type { PieceColor, Square } from "../schema.js";
 
+const BASE_RANGE = 7;
+
+/**
+ * Read the RangeBonus fact for a piece and compute the effective maxSteps
+ * per ray. The bonus is clamped so maxSteps stays within [0, BASE_RANGE].
+ * Absent fact → bonus of 0 → maxSteps = BASE_RANGE (standard full range).
+ */
+function getRangeMaxSteps(session: Session, pieceId: EntityId): number {
+  const value = session.get(pieceId, "RangeBonus");
+  const rangeBonus = value !== undefined ? (value as number) : 0;
+  return Math.min(BASE_RANGE, Math.max(0, BASE_RANGE + rangeBonus));
+}
+
 /**
  * Walk each ray in `rays` from the piece outward, emitting legal moves
- * until a blocker is hit.
+ * until a blocker is hit or maxSteps squares have been traversed.
  */
 function getSlidingMoves(
   session: Session,
@@ -38,10 +57,14 @@ function getSlidingMoves(
   from: Square,
   color: PieceColor,
   rays: Square[][],
+  maxSteps: number,
 ): LegalMove[] {
   const moves: LegalMove[] = [];
   for (const ray of rays) {
+    let steps = 0;
     for (const to of ray) {
+      if (steps >= maxSteps) break;
+      steps++;
       if (isAllyAt(session, to, color)) {
         // Own piece blocks — do not include this square, stop the ray.
         break;
@@ -66,7 +89,8 @@ export function getLegalBishopMoves(
   const from = getPiecePosition(session, pieceId);
   const color = getPieceColor(session, pieceId);
   if (from === null || color === null) return [];
-  return getSlidingMoves(session, pieceId, from, color, bishopCandidates(from));
+  const maxSteps = getRangeMaxSteps(session, pieceId);
+  return getSlidingMoves(session, pieceId, from, color, bishopCandidates(from), maxSteps);
 }
 
 /** Get all legal rook moves for the given rook entity. */
@@ -77,7 +101,8 @@ export function getLegalRookMoves(
   const from = getPiecePosition(session, pieceId);
   const color = getPieceColor(session, pieceId);
   if (from === null || color === null) return [];
-  return getSlidingMoves(session, pieceId, from, color, rookCandidates(from));
+  const maxSteps = getRangeMaxSteps(session, pieceId);
+  return getSlidingMoves(session, pieceId, from, color, rookCandidates(from), maxSteps);
 }
 
 /** Get all legal queen moves for the given queen entity. */
@@ -88,5 +113,6 @@ export function getLegalQueenMoves(
   const from = getPiecePosition(session, pieceId);
   const color = getPieceColor(session, pieceId);
   if (from === null || color === null) return [];
-  return getSlidingMoves(session, pieceId, from, color, queenCandidates(from));
+  const maxSteps = getRangeMaxSteps(session, pieceId);
+  return getSlidingMoves(session, pieceId, from, color, queenCandidates(from), maxSteps);
 }