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/files/data-access.ts

@@ -265,6 +265,26 @@ export const getFileStats = cache(
   },
 )
 
+/**
+ * 按 URL 查询文件附件（用于头像等场景的旧文件清理）
+ */
+export const getFileByUrl = cache(
+  async (url: string): Promise<FileAttachment | null> => {
+    try {
+      const [row] = await db
+        .select()
+        .from(fileAttachments)
+        .where(eq(fileAttachments.url, url))
+        .limit(1)
+
+      return row ? mapRow(row) : null
+    } catch (error) {
+      console.error("getFileByUrl failed:", error)
+      return null
+    }
+  },
+)
+
 /**
  * 按 ID 列表批量查询文件（用于批量删除前获取磁盘路径）
  */