feat(auth): 添加忘记密码功能

- 添加忘记密码页面，支持通过邮箱重置密码
- 添加重置密码页面
- 登录页面添加忘记密码链接
- 添加邮件发送功能
- 完善所有8种语言的翻译 (en-US, zh-CN, ja-JP, ko-KR, de-DE, fr-FR, it-IT, ug-CN)

src/auth.ts

@@ -3,19 +3,42 @@ import { prismaAdapter } from "better-auth/adapters/prisma";
 import { nextCookies } from "better-auth/next-js";
 import { prisma } from "./lib/db";
 import { username } from "better-auth/plugins";
+import {
+  sendEmail,
+  generateVerificationEmailHtml,
+  generateResetPasswordEmailHtml,
+} from "./lib/email";
 
 export const auth = betterAuth({
-    database: prismaAdapter(prisma, {
-        provider: "postgresql"
-    }),
-    emailAndPassword: {
-        enabled: true
+  database: prismaAdapter(prisma, {
+    provider: "postgresql",
+  }),
+  emailAndPassword: {
+    enabled: true,
+    requireEmailVerification: true,
+    sendResetPassword: async ({ user, url }) => {
+      void sendEmail({
+        to: user.email,
+        subject: "重置您的密码 - Learn Languages",
+        html: generateResetPasswordEmailHtml(url, user.name || "用户"),
+      });
     },
-    socialProviders: {
-        github: {
-            clientId: process.env.GITHUB_CLIENT_ID as string,
-            clientSecret: process.env.GITHUB_CLIENT_SECRET as string
-        },
+  },
+  emailVerification: {
+    sendOnSignUp: true,
+    sendVerificationEmail: async ({ user, url }) => {
+      void sendEmail({
+        to: user.email,
+        subject: "验证您的邮箱 - Learn Languages",
+        html: generateVerificationEmailHtml(url, user.name || "用户"),
+      });
     },
-    plugins: [nextCookies(), username()]
+  },
+  socialProviders: {
+    github: {
+      clientId: process.env.GITHUB_CLIENT_ID as string,
+      clientSecret: process.env.GITHUB_CLIENT_SECRET as string,
+    },
+  },
+  plugins: [nextCookies(), username()],
 });