feat: 修改字母描红逻辑，添加字母手写字体

miniprogram/englishPages/shared/data/alphabet.ts

@@ -0,0 +1,39 @@
+/**
+ * 26 字母与示例词（首版用 emoji 占位配图，后续可换 imageUrl）
+ */
+export interface AlphabetEntry {
+    word: string;
+    /** 与单词相关的 emoji，Canvas 上直接绘制，无需图片资源 */
+    emoji: string;
+}
+
+export const ALPHABET_BY_LETTER: Record<string, AlphabetEntry> = {
+    A: { word: 'Apple', emoji: '🍎' },
+    B: { word: 'Ball', emoji: '⚽' },
+    C: { word: 'Cat', emoji: '🐱' },
+    D: { word: 'Dog', emoji: '🐶' },
+    E: { word: 'Egg', emoji: '🥚' },
+    F: { word: 'Fish', emoji: '🐟' },
+    G: { word: 'Girl', emoji: '👧' },
+    H: { word: 'House', emoji: '🏠' },
+    I: { word: 'Ice', emoji: '🧊' },
+    J: { word: 'Juice', emoji: '🧃' },
+    K: { word: 'Kite', emoji: '🪁' },
+    L: { word: 'Lion', emoji: '🦁' },
+    M: { word: 'Moon', emoji: '🌙' },
+    N: { word: 'Nest', emoji: '🪺' },
+    O: { word: 'Orange', emoji: '🍊' },
+    P: { word: 'Pig', emoji: '🐷' },
+    Q: { word: 'Queen', emoji: '👑' },
+    R: { word: 'Rain', emoji: '🌧️' },
+    S: { word: 'Sun', emoji: '☀️' },
+    T: { word: 'Tree', emoji: '🌳' },
+    U: { word: 'Umbrella', emoji: '☂️' },
+    V: { word: 'Van', emoji: '🚐' },
+    W: { word: 'Water', emoji: '💧' },
+    X: { word: 'X-ray', emoji: '🦴' },
+    Y: { word: 'Yacht', emoji: '⛵' },
+    Z: { word: 'Zebra', emoji: '🦓' },
+};
+
+export const LETTERS_UPPER = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');