feat(school,classes): 实现 P2 长期问题全量改进项

P2-2: 新增 OrgTreeNav 组件（学校→年级→班级三级树形导航，支持搜索过滤/选中高亮/展开折叠）

P2-3: 新增 promoteGradesAction 年级升级功能（中文数字/阿拉伯数字识别，按 order 降序避免冲突）

P2-4: 新增 bulkEnrollStudentsAction（CSV 批量导入学生）+ bulkAssignSubjectTeachersAction（CSV 批量分配教师）

P2-5: 为 department/academicYear/grade 的 9 个 CRUD Action 补充 logAudit 审计日志

同步更新架构图文档 004/005

src/modules/school/data-access.ts

@@ -1,7 +1,7 @@
 import "server-only"
 
 import { cache } from "react"
-import { and, asc, eq, inArray, or, sql } from "drizzle-orm"
+import { and, asc, desc, eq, inArray, or, sql } from "drizzle-orm"
 
 import { db } from "@/shared/db"
 import { academicYears, departments, grades, roles, schools, subjects, users, usersToRoles } from "@/shared/db/schema"
@@ -15,6 +15,7 @@ import type {
   GradeInsertData,
   GradeListItem,
   GradeUpdateData,
+  OrgTreeNode,
   SchoolInsertData,
   SchoolListItem,
   SchoolUpdateData,
@@ -595,6 +596,24 @@ export const getSubjectNameById = cache(
   },
 )
 
+/**
+ * 批量获取科目名称映射（subjectId -> name）。
+ * 供跨模块调用使用，避免直接查询 subjects 表。
+ */
+export const getSubjectNameMapByIds = cache(
+  async (subjectIds: string[]): Promise<Map<string, string | null>> => {
+    const ids = subjectIds.filter((id) => id.trim().length > 0)
+    if (ids.length === 0) return new Map()
+    const rows = await db
+      .select({ id: subjects.id, name: subjects.name })
+      .from(subjects)
+      .where(inArray(subjects.id, ids))
+    const map = new Map<string, string | null>()
+    for (const r of rows) map.set(r.id, r.name)
+    return map
+  },
+)
+
 // ---------------------------------------------------------------------------
 // Cross-module query interfaces — grade head/teaching head verification
 // ---------------------------------------------------------------------------
@@ -668,3 +687,114 @@ export const findGradeIdByHeadAndName = cache(async (
     .limit(1)
   return row?.id ?? null
 })
+
+/**
+ * 将年级名称升级：一年级→二年级，1年级→2年级，Grade 1→Grade 2
+ * 无法识别的名称保持不变。
+ */
+function promoteGradeName(name: string): string {
+  // 中文数字映射
+  const chineseNums = ["一", "二", "三", "四", "五", "六", "七", "八", "九", "十", "十一", "十二"]
+  for (let i = 0; i < chineseNums.length - 1; i++) {
+    if (name.includes(chineseNums[i]) && !name.includes(chineseNums[i + 1])) {
+      return name.replace(chineseNums[i], chineseNums[i + 1])
+    }
+  }
+
+  // 阿拉伯数字
+  const match = name.match(/(\d+)/)
+  if (match) {
+    const num = parseInt(match[1], 10)
+    if (num > 0 && num < 13) {
+      return name.replace(match[1], String(num + 1))
+    }
+  }
+
+  return name
+}
+
+/**
+ * 年级升级：将指定学校下的所有年级 order +1，并更新年级名称（如果符合数字模式）。
+ * 例如：一年级 → 二年级，order 1 → 2
+ *
+ * 注意：此函数只更新年级本身的 order 和 name，不迁移班级数据。
+ * 班级升级应由 classes 模块的独立 Action 处理。
+ */
+export async function promoteGrades(schoolId: string): Promise<{ promoted: number }> {
+  const rows = await db
+    .select({ id: grades.id, name: grades.name, order: grades.order })
+    .from(grades)
+    .where(eq(grades.schoolId, schoolId))
+    .orderBy(desc(grades.order)) // 从高到低升级，避免唯一约束冲突
+
+  let promoted = 0
+  for (const row of rows) {
+    const newOrder = (row.order ?? 0) + 1
+    const newName = promoteGradeName(row.name)
+    await db
+      .update(grades)
+      .set({ order: newOrder, name: newName })
+      .where(eq(grades.id, row.id))
+    promoted += 1
+  }
+
+  return { promoted }
+}
+
+/**
+ * 获取学校→年级→班级三级组织架构树。
+ * 班级数据通过 classes 模块的 data-access 动态导入获取，避免循环依赖。
+ * 任何一层查询失败均返回空数组，保证调用方拿到稳定结构。
+ */
+export const getOrgTree = cache(async (): Promise<OrgTreeNode[]> => {
+  try {
+    const [schoolList, gradeList] = await Promise.all([getSchools(), getGrades()])
+
+    const { getAdminClasses } = await import("@/modules/classes/data-access")
+    const allClasses = await getAdminClasses()
+
+    const classesByGradeId = new Map<string, OrgTreeNode[]>()
+    for (const cls of allClasses) {
+      const gradeId = cls.gradeId
+      if (typeof gradeId !== "string" || gradeId.length === 0) continue
+      const node: OrgTreeNode = {
+        id: cls.id,
+        name: cls.name,
+        type: "class",
+      }
+      const list = classesByGradeId.get(gradeId)
+      if (list) {
+        list.push(node)
+      } else {
+        classesByGradeId.set(gradeId, [node])
+      }
+    }
+
+    const gradesBySchoolId = new Map<string, OrgTreeNode[]>()
+    for (const grade of gradeList) {
+      const children = classesByGradeId.get(grade.id) ?? []
+      const node: OrgTreeNode = {
+        id: grade.id,
+        name: grade.name,
+        type: "grade",
+        children,
+      }
+      const list = gradesBySchoolId.get(grade.school.id)
+      if (list) {
+        list.push(node)
+      } else {
+        gradesBySchoolId.set(grade.school.id, [node])
+      }
+    }
+
+    return schoolList.map((school) => ({
+      id: school.id,
+      name: school.name,
+      type: "school",
+      children: gradesBySchoolId.get(school.id) ?? [],
+    }))
+  } catch (error) {
+    console.error("getOrgTree failed:", error)
+    return []
+  }
+})