refactor(modules): update existing module implementations across attendance, audit, auth, classes, course-plans, exams, files, homework, layout, proctoring, questions, scheduling, textbooks, users

- Update attendance components and data-access for record management

- Update audit log views, filters, and data-access

- Update auth login and register forms

- Update classes actions, components, and data-access (admin, schedule, stats)

- Update course-plans actions, form, list, progress, and schema

- Update exams actions, AI pipeline, preview components, and hooks

- Update files components (icon, list, preview, upload) and data-access

- Update homework assignment form, review view, auto-save hook, and stats-service

- Update layout sidebar, header, and navigation config

- Update proctoring actions, anti-cheat monitor, and data-access

- Update questions actions, components (dialog, actions, columns, filters), and data-access

- Update scheduling actions, auto-scheduler, components, and schema

- Update textbooks constants and text-selection hook

- Update users class-registration, import-dialog, data-access, and user-service

src/modules/auth/components/login-form.tsx

@@ -8,18 +8,23 @@ import { Button } from "@/shared/components/ui/button"
 import { Input } from "@/shared/components/ui/input"
 import { Label } from "@/shared/components/ui/label"
 import { cn } from "@/shared/lib/utils"
-import { Loader2, Github } from "lucide-react"
+import { Loader2, Github, ShieldCheck } from "lucide-react"
+import { preflightTwoFactorAction } from "@/modules/settings/actions-security"
 
 type LoginFormProps = React.HTMLAttributes<HTMLDivElement>
 
 export function LoginForm({ className, ...props }: LoginFormProps) {
   const [isLoading, setIsLoading] = React.useState<boolean>(false)
+  const [requiresTwoFactor, setRequiresTwoFactor] = React.useState<boolean>(false)
+  const [totpCode, setTotpCode] = React.useState<string>("")
+  const [error, setError] = React.useState<string>("")
   const router = useRouter()
   const searchParams = useSearchParams()
 
   async function onSubmit(event: React.SyntheticEvent) {
     event.preventDefault()
     setIsLoading(true)
+    setError("")
 
     const form = event.currentTarget as HTMLFormElement
     const formData = new FormData(form)
@@ -27,10 +32,25 @@ export function LoginForm({ className, ...props }: LoginFormProps) {
     const password = String(formData.get("password") ?? "")
     const callbackUrl = searchParams.get("callbackUrl") ?? "/dashboard"
 
+    // 首次提交：检查是否需要 2FA
+    if (!requiresTwoFactor) {
+      try {
+        const preflight = await preflightTwoFactorAction(email)
+        if (preflight.required) {
+          setRequiresTwoFactor(true)
+          setIsLoading(false)
+          return
+        }
+      } catch {
+        // 预检失败时静默降级为普通登录
+      }
+    }
+
     const result = await signIn("credentials", {
       redirect: false,
       email,
       password,
+      totpCode: requiresTwoFactor ? totpCode : undefined,
       callbackUrl,
     })
 
@@ -39,6 +59,13 @@ export function LoginForm({ className, ...props }: LoginFormProps) {
     if (!result?.error) {
       router.push(result?.url ?? callbackUrl)
       router.refresh()
+    } else {
+      // 2FA 验证码错误时保留 2FA 输入框，允许用户重新输入
+      if (requiresTwoFactor) {
+        setError("Invalid 2FA code. Please try again.")
+      } else {
+        setError("Invalid email or password.")
+      }
     }
   }
 
@@ -49,47 +76,91 @@ export function LoginForm({ className, ...props }: LoginFormProps) {
           Welcome back
         </h1>
         <p className="text-sm text-muted-foreground">
-          Enter your email to sign in to your account
+          {requiresTwoFactor
+            ? "Enter the 6-digit code from your authenticator app"
+            : "Enter your email to sign in to your account"}
         </p>
       </div>
       <form onSubmit={onSubmit}>
         <div className="grid gap-4">
-          <div className="grid gap-2">
-            <Label htmlFor="email">Email</Label>
-            <Input
-              id="email"
-              name="email"
-              placeholder="name@example.com"
-              type="email"
-              autoCapitalize="none"
-              autoComplete="email"
-              autoCorrect="off"
-              disabled={isLoading}
-            />
-          </div>
-          <div className="grid gap-2">
-            <div className="flex items-center justify-between">
-              <Label htmlFor="password">Password</Label>
-              <Link
-                href="/forgot-password"
-                className="text-sm font-medium text-muted-foreground hover:underline"
+          {!requiresTwoFactor ? (
+            <>
+              <div className="grid gap-2">
+                <Label htmlFor="email">Email</Label>
+                <Input
+                  id="email"
+                  name="email"
+                  placeholder="name@example.com"
+                  type="email"
+                  autoCapitalize="none"
+                  autoComplete="email"
+                  autoCorrect="off"
+                  disabled={isLoading}
+                />
+              </div>
+              <div className="grid gap-2">
+                <div className="flex items-center justify-between">
+                  <Label htmlFor="password">Password</Label>
+                  <Link
+                    href="/forgot-password"
+                    className="text-sm font-medium text-muted-foreground hover:underline"
+                  >
+                    Forgot password?
+                  </Link>
+                </div>
+                <Input
+                  id="password"
+                  name="password"
+                  type="password"
+                  autoComplete="current-password"
+                  disabled={isLoading}
+                />
+              </div>
+            </>
+          ) : (
+            <div className="grid gap-2">
+              <Label htmlFor="totpCode" className="flex items-center gap-1.5">
+                <ShieldCheck className="h-4 w-4" />
+                2FA Code
+              </Label>
+              <Input
+                id="totpCode"
+                name="totpCode"
+                type="text"
+                inputMode="numeric"
+                autoComplete="one-time-code"
+                placeholder="123456"
+                maxLength={8}
+                value={totpCode}
+                onChange={(e) => setTotpCode(e.target.value)}
+                disabled={isLoading}
+                autoFocus
+              />
+              <p className="text-xs text-muted-foreground">
+                Enter your 6-digit authenticator code or an 8-character backup code.
+              </p>
+              <button
+                type="button"
+                onClick={() => {
+                  setRequiresTwoFactor(false)
+                  setTotpCode("")
+                  setError("")
+                }}
+                className="text-xs text-muted-foreground hover:underline justify-self-start"
+                disabled={isLoading}
               >
-                Forgot password?
-              </Link>
+                ← Back to login
+              </button>
             </div>
-            <Input
-              id="password"
-              name="password"
-              type="password"
-              autoComplete="current-password"
-              disabled={isLoading}
-            />
-          </div>
+          )}
+          {error ? (
+            <p className="text-sm text-red-600">{error}</p>
+          ) : null}
           <Button disabled={isLoading}>
             {isLoading && (
               <Loader2 className="mr-2 h-4 w-4 animate-spin" />
             )}
-            Sign In with Email
+            {requiresTwoFactor ? "Verify & Sign In" : "Sign In with Email"}
           </Button>
         </div>
       </form>