M1.1: Fix PathfindingSystem tile size — 64→32 via config injection

PathfindingSystem constructor now accepts optional {tileWidth, tileHeight}
config param with 64px defaults for backward compat.
SystemOrchestrator.initPathfinding() reads tilemap.tileWidth/tileHeight
and passes them through. Verification console.log added to initGrid().

6 new tests:
- Constructor accepts config / defaults to 64 / empty config → 64
- worldToTileCoords: 32px tiles → (1,1), 64px tiles → (2,1), default
All 32 PathfindingSystem tests pass, zero regressions (167 total).

src/systems/PathfindingSystem.js

@@ -11,8 +11,9 @@ export default class PathfindingSystem {
   /**
    * @param {Phaser.Scene} scene
    * @param {Phaser.Tilemaps.Tilemap} tilemap
+   * @param {{tileWidth?: number, tileHeight?: number}} [config]
    */
-  constructor(scene, tilemap) {
+  constructor(scene, tilemap, config = {}) {
     this.scene = scene;
     this.tilemap = tilemap;
 
@@ -26,10 +27,10 @@ export default class PathfindingSystem {
     this.grid = [];
 
     /** @type {number} tile width in pixels (default 64) */
-    this.tileWidth = 64;
+    this.tileWidth = config.tileWidth || 64;
 
     /** @type {number} tile height in pixels (default 64) */
-    this.tileHeight = 64;
+    this.tileHeight = config.tileHeight || 64;
 
     /** @type {boolean} whether the grid has been initialized */
     this._initialized = false;
@@ -109,6 +110,10 @@ export default class PathfindingSystem {
     // Set diagonal cost multiplier
     this.easystar.setAdditionalPointCost(1.5);
 
+    console.log(
+      `[PathfindingSystem] initGrid: ${width}x${height} grid, tile size ${this.tileWidth}x${this.tileHeight}px`
+    );
+
     this._initialized = true;
   }
 

src/systems/SystemOrchestrator.js

@@ -159,9 +159,14 @@ export default class SystemOrchestrator {
       this.systems.pathfinding = null;
     }
 
+    const tilemap = this.systems.map.tilemap;
+    const tileWidth = tilemap.tileWidth || 32;
+    const tileHeight = tilemap.tileHeight || 32;
+
     this.systems.pathfinding = new PathfindingSystem(
       this.scene,
-      this.systems.map.tilemap,
+      tilemap,
+      { tileWidth, tileHeight },
     );
 
     this.systems.pathfinding.initGrid('Rocks', 'Floor');

tests/unit/PathfindingSystem.test.js

@@ -339,6 +339,57 @@ describe('PathfindingSystem', () => {
     });
   });
 
+  // ── config constructor ──────────────────────────────────────────
+  describe('config constructor', () => {
+    test('constructor accepts config for tileWidth and tileHeight', () => {
+      const pf = new PathfindingSystem(mockScene, mockTilemap, {
+        tileWidth: 32,
+        tileHeight: 32,
+      });
+      expect(pf.tileWidth).toBe(32);
+      expect(pf.tileHeight).toBe(32);
+    });
+
+    test('constructor defaults to 64 when no config provided', () => {
+      const pf = new PathfindingSystem(mockScene, mockTilemap);
+      expect(pf.tileWidth).toBe(64);
+      expect(pf.tileHeight).toBe(64);
+    });
+
+    test('constructor defaults to 64 when config lacks tile dimensions', () => {
+      const pf = new PathfindingSystem(mockScene, mockTilemap, {});
+      expect(pf.tileWidth).toBe(64);
+      expect(pf.tileHeight).toBe(64);
+    });
+  });
+
+  // ── worldToTileCoords with configurable tile size ────────────────
+  describe('worldToTileCoords with config', () => {
+    test('worldToTileCoords(32, 32) returns (1, 1) with 32px tiles', () => {
+      const pf = new PathfindingSystem(mockScene, mockTilemap, {
+        tileWidth: 32,
+        tileHeight: 32,
+      });
+      const result = pf.worldToTileCoords(32, 32);
+      expect(result).toEqual({ x: 1, y: 1 });
+    });
+
+    test('worldToTileCoords(128, 64) returns (2, 1) with 64px tiles (backward compat)', () => {
+      const pf = new PathfindingSystem(mockScene, mockTilemap, {
+        tileWidth: 64,
+        tileHeight: 64,
+      });
+      const result = pf.worldToTileCoords(128, 64);
+      expect(result).toEqual({ x: 2, y: 1 });
+    });
+
+    test('worldToTileCoords with default 64px tiles matches legacy behavior', () => {
+      const pf = new PathfindingSystem(mockScene, mockTilemap);
+      const result = pf.worldToTileCoords(150, 200);
+      expect(result).toEqual({ x: 2, y: 3 });
+    });
+  });
+
   // ── update loop ─────────────────────────────────────────────────
   describe('update', () => {
     test('does not throw when called', () => {