feat(student): 完成 student 模块 v4 剩余修复

- P1-4.2: 新增班级详情页 courses/[classId]，展示教师/学校/教室信息与课表

- P2-2.5: 今日课表卡片高亮当前/下一节课（useMemo 实时计算）

- P2-3.9: 作业作答进度网格支持点击跳转题目（scrollIntoView）

- P2-3.10: 作业复习视图显示正确答案（选择/判断/文本题）

- P2-4.4: 课程列表支持按班级名/教师/学校搜索

- P2-5.2: 成绩页新增趋势折线图组件 GradeTrendCard

- P2-9.2/9.3: 诊断报告新增历史记录卡片与弱点练习入口

- P2-10.2: 选课列表支持搜索与选课模式筛选

- P2-11.3: 修复教材阅读页全屏溢出

- P3-1.5: 面包屑保留首个角色段作为根上下文

- P3-7.3: 课表项支持点击跳转至班级详情页（ScheduleList href）

src/modules/student/components/student-courses-view.tsx

@@ -11,7 +11,7 @@ import { Button } from "@/shared/components/ui/button"
 import { EmptyState } from "@/shared/components/ui/empty-state"
 import { Input } from "@/shared/components/ui/input"
 import { Label } from "@/shared/components/ui/label"
-import { BookOpen, Building2, Inbox, CalendarDays, User, PlusCircle, PenTool } from "lucide-react"
+import { BookOpen, Building2, Inbox, CalendarDays, User, PlusCircle, PenTool, Mail, School } from "lucide-react"
 
 import type { StudentEnrolledClass } from "@/modules/classes/types"
 import { joinClassByInvitationCodeAction } from "@/modules/classes/actions"
@@ -22,7 +22,11 @@ const ClassCard = memo(function ClassCard({ c }: { c: StudentEnrolledClass }) {
       <CardHeader className="bg-muted/30 pb-4">
         <div className="flex items-start justify-between gap-4">
           <div className="space-y-1">
-            <CardTitle className="line-clamp-1 text-lg">{c.name}</CardTitle>
+            <CardTitle className="line-clamp-1 text-lg">
+              <Link href={`/student/learning/courses/${encodeURIComponent(c.id)}`} className="hover:underline">
+                {c.name}
+              </Link>
+            </CardTitle>
             <CardDescription className="flex items-center gap-2 text-xs">
               <span className="flex items-center gap-1">
                 <BookOpen className="h-3 w-3" />
@@ -44,12 +48,26 @@ const ClassCard = memo(function ClassCard({ c }: { c: StudentEnrolledClass }) {
 
       <CardContent className="flex-1 space-y-4 py-4">
         <div className="space-y-2 text-sm">
+          {c.schoolName && (
+            <div className="flex items-center gap-2 text-muted-foreground">
+              <School className="h-4 w-4" />
+              <span>{c.schoolName}</span>
+            </div>
+          )}
           {c.teacherName && (
             <div className="flex items-center gap-2 text-muted-foreground">
               <User className="h-4 w-4" />
               <span>{c.teacherName}</span>
             </div>
           )}
+          {c.teacherEmail && (
+            <div className="flex items-center gap-2 text-muted-foreground">
+              <Mail className="h-4 w-4" />
+              <a href={`mailto:${c.teacherEmail}`} className="hover:underline hover:text-foreground">
+                {c.teacherEmail}
+              </a>
+            </div>
+          )}
           {c.room && (
             <div className="flex items-center gap-2 text-muted-foreground">
               <Building2 className="h-4 w-4" />
@@ -60,6 +78,12 @@ const ClassCard = memo(function ClassCard({ c }: { c: StudentEnrolledClass }) {
       </CardContent>
 
       <CardFooter className="flex gap-2 border-t bg-muted/10 p-4">
+        <Button asChild variant="outline" size="sm" className="flex-1">
+          <Link href={`/student/learning/courses/${encodeURIComponent(c.id)}`}>
+            <BookOpen className="mr-2 h-4 w-4" />
+            Details
+          </Link>
+        </Button>
         <Button asChild variant="outline" size="sm" className="flex-1">
           <Link href={`/student/schedule?classId=${encodeURIComponent(c.id)}`}>
             <CalendarDays className="mr-2 h-4 w-4" />
@@ -118,21 +142,24 @@ export function StudentCoursesView({
         <EmptyState
           icon={Inbox}
           title="No courses yet"
-          description="You are not enrolled in any classes. Join a class to get started."
+          description="You are not enrolled in any classes. Join a class below to get started."
           className="py-12"
         />
       )}
 
-      <div className="rounded-lg border bg-card p-6 shadow-sm">
-        <div className="mb-6 flex items-center gap-3">
-          <div className="flex h-10 w-10 items-center justify-center rounded-full bg-primary/10">
-            <PlusCircle className="h-5 w-5 text-primary" />
-          </div>
-          <div>
-            <h3 className="text-lg font-semibold">Join a Class</h3>
-            <p className="text-sm text-muted-foreground">
-              Enter the invitation code provided by your teacher to enroll.
-            </p>
+      {/* 加入班级表单：无课程时置顶，有课程时置底 */}
+      <div className={classes.length === 0 ? "" : "rounded-lg border bg-card p-6 shadow-sm"}>
+        <div className={classes.length === 0 ? "rounded-lg border bg-card p-6 shadow-sm" : "mb-6 flex items-center gap-3"}>
+          <div className={classes.length === 0 ? "mb-6 flex items-center gap-3" : ""}>
+            <div className="flex h-10 w-10 items-center justify-center rounded-full bg-primary/10">
+              <PlusCircle className="h-5 w-5 text-primary" />
+            </div>
+            <div>
+              <h3 className="text-lg font-semibold">Join a Class</h3>
+              <p className="text-sm text-muted-foreground">
+                Enter the invitation code provided by your teacher to enroll.
+              </p>
+            </div>
           </div>
         </div>