feat(auth): 邮箱验证码登录通道（正式兜底，替代不可用的短信）——/auth/email/code + /auth/email/login，SmtpEmailSender（stdlib smtplib，无新依赖）+ FakeEmailSender（仅本地）；频控对齐短信口径（60s 冷却/邮箱 1h≤5·24h≤10/IP≤20/设备≤10）；新增 EMAIL_*/SMTP_* 配置与 40112/40113/42912/42913/61001 错误码

apps/api/main.py

@@ -15,6 +15,7 @@ from apps.api.deps import build_llm_gateway
 from apps.api.routers import (
     agent,
     auth,
+    auth_email,
     auth_sms,
     events,
     health,
@@ -84,6 +85,7 @@ def create_app(settings: Settings | None = None) -> FastAPI:
     routers = (
         auth.router,
         auth_sms.router,
+        auth_email.router,
         agent.router,
         quota.router,
         tasks.router,