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/app/(dashboard)/student/grades/page.tsx

@@ -1,19 +1,34 @@
 import { getAuthContext } from "@/shared/lib/auth-guard"
 import { getStudentGradeSummary } from "@/modules/grades/data-access"
 import { StudentGradeSummary } from "@/modules/grades/components/student-grade-summary"
+import { GradeFilters } from "@/modules/grades/components/grade-filters"
+import { GradeTrendCard } from "@/modules/grades/components/grade-trend-card"
 import { EmptyState } from "@/shared/components/ui/empty-state"
 import { UserX } from "lucide-react"
 
 export const dynamic = "force-dynamic"
 
-export default async function StudentGradesPage() {
-  const ctx = await getAuthContext()
+type SearchParams = { [key: string]: string | string[] | undefined }
 
-  const summary = await getStudentGradeSummary(ctx.userId)
+const getParam = (params: SearchParams, key: string) => {
+  const v = params[key]
+  return Array.isArray(v) ? v[0] : v
+}
+
+export default async function StudentGradesPage({
+  searchParams,
+}: {
+  searchParams: Promise<SearchParams>
+}) {
+  const ctx = await getAuthContext()
+  const [sp, summary] = await Promise.all([
+    searchParams,
+    getStudentGradeSummary(ctx.userId),
+  ])
 
   if (!summary) {
     return (
-      <div className="h-full flex-1 flex-col space-y-8 p-8 md:flex">
+      <div className="space-y-8">
         <div>
           <h2 className="text-2xl font-bold tracking-tight">My Grades</h2>
           <p className="text-muted-foreground">View your grade records.</p>
@@ -28,13 +43,34 @@ export default async function StudentGradesPage() {
     )
   }
 
+  // 应用筛选
+  const q = (getParam(sp, "q") || "").toLowerCase().trim()
+  const subjectFilter = getParam(sp, "subject") || "all"
+  const typeFilter = getParam(sp, "type") || "all"
+  const semesterFilter = getParam(sp, "semester") || "all"
+
+  const filteredRecords = summary.records.filter((r) => {
+    if (q && !r.title.toLowerCase().includes(q)) return false
+    if (subjectFilter !== "all" && r.subjectName !== subjectFilter) return false
+    if (typeFilter !== "all" && r.type !== typeFilter) return false
+    if (semesterFilter !== "all" && r.semester !== semesterFilter) return false
+    return true
+  })
+
+  const filteredSummary = {
+    ...summary,
+    records: filteredRecords,
+  }
+
   return (
-    <div className="h-full flex-1 flex-col space-y-8 p-8 md:flex">
+    <div className="space-y-8">
       <div>
         <h2 className="text-2xl font-bold tracking-tight">My Grades</h2>
         <p className="text-muted-foreground">View your grade records.</p>
       </div>
-      <StudentGradeSummary summary={summary} />
+      <GradeFilters />
+      {filteredSummary.records.length > 0 && <GradeTrendCard summary={filteredSummary} />}
+      <StudentGradeSummary summary={filteredSummary} />
     </div>
   )
 }