feat(01-02): implement Tile model class

- Implements Tile interface from types/index.ts
- Constructor with id, type, position
- emoji getter returns CONFIG.emojis[type]
- isAdjacent() checks orthogonal adjacency
- cleared property defaults to false

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/models/Tile.ts

@@ -0,0 +1,47 @@
+// src/models/Tile.ts - Tile data model
+/**
+ * Tile represents a single tile in the game grid.
+ * It contains position, type, and state information.
+ */
+
+import { TilePosition, Tile as TileInterface } from '../types';
+import { CONFIG } from '../config';
+
+export class Tile implements TileInterface {
+  /**
+   * Whether this tile has been cleared from the board
+   */
+  public cleared: boolean = false;
+
+  /**
+   * Creates a new Tile
+   * @param id - Unique identifier for this tile
+   * @param type - Tile type (0-15 for emoji index)
+   * @param position - Grid position (row, col)
+   */
+  constructor(
+    public readonly id: string,
+    public readonly type: number,
+    public readonly position: TilePosition
+  ) {}
+
+  /**
+   * Gets the emoji for this tile's type
+   */
+  get emoji(): string {
+    return CONFIG.emojis[this.type];
+  }
+
+  /**
+   * Checks if this tile is orthogonally adjacent to another tile
+   * @param other - The other tile to check
+   * @returns true if tiles are adjacent (not diagonal)
+   */
+  isAdjacent(other: Tile): boolean {
+    const rowDiff = Math.abs(this.position.row - other.position.row);
+    const colDiff = Math.abs(this.position.col - other.position.col);
+
+    // Orthogonally adjacent means exactly one row OR one column difference, but not both
+    return (rowDiff === 1 && colDiff === 0) || (rowDiff === 0 && colDiff === 1);
+  }
+}