feat(admin-portal): 完成参考项目差距闭环 - 4 批次补齐 + Vitest 测试

差距分析闭环（workline §7-§8）：
- P0：审计子模块 3 页 + 学校组织 7 页
- P1：系统设置 4 Card + 公告管理 + 邀请码管理
- P2：文件管理 + AI 配置
- P6：5 测试文件 / 69 用例全过

共享基础设施：
- permissions +11 权限点 +14 路由
- view-models +20 接口
- i18n +100 key
- graphql-client +25 operation
- fixtures/handlers +15 mock +20 handler

质量：typecheck + lint 零错误，vitest 69/69 通过，arch.db 已更新

apps/admin-portal/src/app/admin/school/academic-year/page.tsx

@@ -0,0 +1,106 @@
+"use client";
+
+import { type ReactNode } from "react";
+import { useAcademicYears } from "@/hooks/use-school";
+import {
+  PaperCard,
+  LoadingState,
+  ErrorState,
+  EmptyState,
+  Table,
+  TableRow,
+  TableCell,
+} from "@/components/ui";
+import { t } from "@/lib/i18n";
+import type { AcademicYearViewModel } from "@/types/view-models";
+
+function CurrentBadge(): ReactNode {
+  const color = "var(--color-success)";
+  return (
+    <span
+      style={{
+        display: "inline-block",
+        padding: "2px 8px",
+        fontSize: 11,
+        borderRadius: 10,
+        background: `${color}20`,
+        color,
+        border: `1px solid ${color}40`,
+        fontWeight: 500,
+      }}
+    >
+      {t("admin.school.currentYear")}
+    </span>
+  );
+}
+
+export default function AcademicYearPage(): ReactNode {
+  const { data, loading, error } = useAcademicYears();
+
+  return (
+    <PaperCard className="p-4">
+      {loading && <LoadingState />}
+      {error && <ErrorState message={error.message} />}
+      {!loading && !error && (
+        <>
+          {data.length === 0 ? (
+            <EmptyState message={t("admin.common.empty")} />
+          ) : (
+            <Table
+              headers={[
+                "学年",
+                t("admin.school.startDate"),
+                t("admin.school.endDate"),
+                "第一学期",
+                "第二学期",
+                t("admin.common.status"),
+              ]}
+            >
+              {data.map((year: AcademicYearViewModel) => (
+                <TableRow key={year.id}>
+                  <TableCell
+                    style={{
+                      fontWeight: year.isCurrent ? 600 : 500,
+                      color: year.isCurrent
+                        ? "var(--color-accent)"
+                        : "var(--color-ink)",
+                    }}
+                  >
+                    {year.name}
+                  </TableCell>
+                  <TableCell style={{ whiteSpace: "nowrap" }}>
+                    {year.startDate}
+                  </TableCell>
+                  <TableCell style={{ whiteSpace: "nowrap" }}>
+                    {year.endDate}
+                  </TableCell>
+                  <TableCell
+                    style={{
+                      whiteSpace: "nowrap",
+                      fontFamily: "var(--font-mono)",
+                      fontSize: 12,
+                    }}
+                  >
+                    {year.firstSemesterStart} ~ {year.firstSemesterEnd}
+                  </TableCell>
+                  <TableCell
+                    style={{
+                      whiteSpace: "nowrap",
+                      fontFamily: "var(--font-mono)",
+                      fontSize: 12,
+                    }}
+                  >
+                    {year.secondSemesterStart} ~ {year.secondSemesterEnd}
+                  </TableCell>
+                  <TableCell>
+                    {year.isCurrent ? <CurrentBadge /> : "—"}
+                  </TableCell>
+                </TableRow>
+              ))}
+            </Table>
+          )}
+        </>
+      )}
+    </PaperCard>
+  );
+}