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

app/api/resources-import/route.ts

@@ -9,6 +9,7 @@ import {
 import { getRuntimeEnv } from "../../../lib/runtime-env";
 import {
   mergeCooperationSources,
+  mergeTags,
   normalizeProfileUrl,
   parseResourceImportFile,
   RESOURCE_IMPORT_MAX_BYTES,
@@ -27,6 +28,7 @@ type AccountRow = {
   ip_location: string;
   followers: number;
   cooperation_source: string;
+  tags: string;
 };
 
 type AnalyzedRow = ResourceImportRow & {
@@ -34,6 +36,7 @@ type AnalyzedRow = ResourceImportRow & {
   accountId: string;
   platformUid: string;
   cooperationSource: string;
+  tags: string;
 };
 
 function identityKey(platform: string, value: string) {
@@ -46,7 +49,7 @@ async function loadAccounts() {
   return getRawDb()
     .prepare(
       `SELECT id, platform, platform_uid, public_account_id, nickname,
-              profile_url, ip_location, followers, cooperation_source
+              profile_url, ip_location, followers, cooperation_source, tags
        FROM accounts`,
     )
     .all<AccountRow>();
@@ -187,6 +190,7 @@ function analyzeRows(rows: ResourceImportRow[], accountRows: AccountRow[]) {
         existing?.cooperation_source ?? "",
         row.cooperationSource,
       ),
+      tags: mergeTags(existing?.tags ?? "", row.tags),
     };
     if (analyzed.action !== "error") {
       const virtual: AccountRow = {
@@ -199,6 +203,7 @@ function analyzeRows(rows: ResourceImportRow[], accountRows: AccountRow[]) {
         ip_location: row.ipLocation || existing?.ip_location || "待识别",
         followers: row.followers || existing?.followers || 0,
         cooperation_source: analyzed.cooperationSource,
+        tags: analyzed.tags,
       };
       if (row.profileUrl) profileMap.set(identityKey(row.platform, row.profileUrl), virtual);
       if (row.publicAccountId) {
@@ -249,6 +254,7 @@ export async function POST(request: Request) {
           ipLocation: row.ipLocation,
           followers: row.followers,
           cooperationSource: row.cooperationSource,
+          tags: row.tags,
           action: row.action,
           errors: row.errors,
         })),
@@ -275,6 +281,7 @@ export async function POST(request: Request) {
                    WHEN ? != '' AND ? != '待识别' THEN ? ELSE ip_location END,
                  followers = CASE WHEN ? = 1 THEN ? ELSE followers END,
                  cooperation_source = ?,
+                 tags = ?,
                  last_seen_at = CURRENT_TIMESTAMP
                WHERE id = ?`,
             )
@@ -290,6 +297,7 @@ export async function POST(request: Request) {
               row.followersResolved ? 1 : 0,
               row.followers,
               row.cooperationSource,
+              row.tags,
               row.accountId,
             )
         : db
@@ -297,8 +305,8 @@ export async function POST(request: Request) {
               `INSERT INTO accounts
                 (id, platform, platform_uid, public_account_id, nickname,
                  profile_url, ip_location, followers, post_count, avg_views,
-                 cooperation_source)
-               VALUES (?, ?, ?, ?, ?, ?, ?, ?, 0, 0, ?)`,
+                 cooperation_source, tags)
+               VALUES (?, ?, ?, ?, ?, ?, ?, ?, 0, 0, ?, ?)`,
             )
             .bind(
               row.accountId,
@@ -310,6 +318,7 @@ export async function POST(request: Request) {
               row.ipLocation,
               row.followers,
               row.cooperationSource,
+              row.tags,
             ),
     );
     if (statements.length > 0) await db.batch(statements);