feat: add shared types and difficulty constants

src/game/constants.ts

@@ -0,0 +1,32 @@
+import { Difficulty, DifficultyConfig } from "../types";
+
+export const DIFFICULTY_CONFIGS: Record<Difficulty, DifficultyConfig> = {
+  easy: {
+    rows: 4,
+    cols: 6,
+    timerSeconds: 300,
+    hints: 5,
+    shuffles: 3,
+    pairCount: 12,
+  },
+  medium: {
+    rows: 6,
+    cols: 8,
+    timerSeconds: 240,
+    hints: 3,
+    shuffles: 2,
+    pairCount: 24,
+  },
+  hard: {
+    rows: 8,
+    cols: 10,
+    timerSeconds: 180,
+    hints: 1,
+    shuffles: 1,
+    pairCount: 40,
+  },
+};
+
+export const BASE_MATCH_SCORE = 100;
+export const SPEED_BONUS_MAX = 50;
+export const SPEED_BONUS_WINDOW_MS = 5000;

src/types/index.ts

@@ -0,0 +1,24 @@
+export type Difficulty = "easy" | "medium" | "hard";
+
+export interface Point {
+  row: number;
+  col: number;
+}
+
+export type GameStatus = "menu" | "playing" | "paused" | "won" | "lost";
+
+export interface DifficultyConfig {
+  rows: number;
+  cols: number;
+  timerSeconds: number;
+  hints: number;
+  shuffles: number;
+  pairCount: number;
+}
+
+export interface TileData {
+  emoji: string;
+  id: number;
+}
+
+export type Board = (TileData | null)[][];