feat: 在账号资源库中展示导入的标签字段

KOC 资源导入模板新增「标签」列，导入后写入 accounts.tags 并在
账号资源库面板以 badge 形式展示，导出时也带回标签列以保证往返一致。

- lib/resource-import.ts: 新增 tags 字段与 HEADER 别名（标签/账号标签/人设标签），
  新增 normalizeTags/mergeTags 工具，按顿号规整与合并
- 修复 xlsx 解析器对自闭合空 cell (<c r="G6"/>) 的错位 bug，否则
  行内出现空 cell 会让后续 cell 的列引用读到错误 body（如老茄子行标签丢失）
- db/schema.ts + lib/mvp-db.ts: accounts 表新增 tags VARCHAR(500)
- app/api/resources-import/route.ts: SELECT/INSERT/UPDATE/预览全部带上 tags
- app/api/resources-export/route.ts: 导出表加「标签」列
- app/admin-app.tsx + app/globals.css: 资源卡片新增「账号标签」区，
  导入预览行展示标签
- public/KOC资源导入模板.xlsx: 模板补「标签（选填）」列与填写说明
- mysql/0005_account_tags.sql: 线上 MySQL 迁移
- tests/resource-import.test.mjs: 补 tags 解析/合并用例

lib/resource-import.ts

@@ -13,6 +13,7 @@ export type ResourceImportRow = {
   followers: number;
   followersResolved: boolean;
   cooperationSource: string;
+  tags: string;
   errors: string[];
 };
 
@@ -23,6 +24,7 @@ const HEADER_ALIASES = {
   ipLocation: ["IP属地", "IP地址", "IP地区", "IP所在地"],
   followers: ["粉丝数", "粉丝", "粉丝量"],
   cooperationSource: ["合作来源", "资源来源", "历史合作来源"],
+  tags: ["标签", "账号标签", "人设标签"],
 } as const;
 
 type CanonicalHeader = keyof typeof HEADER_ALIASES;
@@ -60,9 +62,11 @@ function parseWorksheet(xml: string, sharedStrings: string[]) {
     const rowAttributes = rowMatch[1];
     const rowNumber = Number(rowAttributes.match(/\br="(\d+)"/)?.[1] ?? rows.length + 1);
     const values: string[] = [];
-    for (const cellMatch of rowMatch[2].matchAll(/<c\b([^>]*)>([\s\S]*?)<\/c>/g)) {
+    for (const cellMatch of rowMatch[2].matchAll(
+      /<c\b([^>]*?)(?:\/>|>([\s\S]*?)<\/c>)/g,
+    )) {
       const attributes = cellMatch[1];
-      const body = cellMatch[2];
+      const body = cellMatch[2] ?? "";
       const reference = attributes.match(/\br="([A-Z]+\d+)"/i)?.[1] ?? "A1";
       const type = attributes.match(/\bt="([^"]+)"/)?.[1] ?? "";
       const rawValue = body.match(/<v>([\s\S]*?)<\/v>/)?.[1] ?? "";
@@ -259,6 +263,7 @@ function normalizeRows(rows: string[][]) {
       followers: parsedFollowers.value,
       followersResolved: parsedFollowers.resolved,
       cooperationSource: valueAt(source, header.mapping, "cooperationSource"),
+      tags: normalizeTags(valueAt(source, header.mapping, "tags")),
       errors,
     });
   }
@@ -320,3 +325,18 @@ export function mergeCooperationSources(existing: string, incoming: string) {
     ),
   ].join("、");
 }
+
+export function normalizeTags(value: string) {
+  return [
+    ...new Set(
+      value
+        .split(/[、,，;；|]/)
+        .map((item) => item.trim())
+        .filter(Boolean),
+    ),
+  ].join("、");
+}
+
+export function mergeTags(existing: string, incoming: string) {
+  return normalizeTags(`${existing}、${incoming}`);
+}