fix(accounts): 完善手机号必绑与账号注销等登录异常分型识别

- 补充必须绑定手机号与账号注销/封禁/冻结等错误文案的识别规则
- 增加数据修正迁移 20261008_0052，回写历史账号和登录任务的失败分型
- 增加列表查询与导出时根据错误文案自动兜底细化 failure_kind 的逻辑
- 增加并完善相关分型单元测试

web/backend/migrations/versions/20261008_0052_relogin_failure_kind_sync.py

@@ -0,0 +1,72 @@
+"""同步历史重登失败分型：根据最新 classify_failure 规则刷正 accounts 和 login_tasks
+
+## 背景
+
+新增了「必须绑定手机号」与「账号注销/封禁」分型，历史已存在报错文案的账号需要回写正确的 failure_kind，
+使「登录异常一键筛选」与列表角标统计准确。
+"""
+
+from __future__ import annotations
+
+import sqlalchemy as sa
+from alembic import op
+from web.backend.services.login_failure import classify_failure
+
+revision: str = "20261008_0052"
+down_revision: str | None = "20261004_0051"
+branch_labels: str | None = None
+depends_on: str | None = None
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+
+    # 1. 查询 accounts 中有 relogin_last_error 的记录
+    rows = conn.execute(
+        sa.text(
+            "SELECT id, relogin_last_error, relogin_failure_kind "
+            "FROM accounts "
+            "WHERE relogin_last_error IS NOT NULL AND relogin_last_error != ''"
+        )
+    ).fetchall()
+
+    for row in rows:
+        acc_id, err_text, current_kind = row[0], row[1], row[2]
+        new_kind = classify_failure(err_text)
+        if new_kind and new_kind != current_kind:
+            conn.execute(
+                sa.text("UPDATE accounts SET relogin_failure_kind = :k WHERE id = :id"),
+                {"k": new_kind, "id": acc_id},
+            )
+
+    # 2. 查询 login_tasks 中有 message 的记录
+    # 检查 login_tasks 是否有 relogin_failure_kind 列
+    col_exists = conn.execute(
+        sa.text(
+            "SELECT COUNT(*) FROM information_schema.columns "
+            "WHERE table_schema = DATABASE() "
+            "AND table_name = 'login_tasks' AND column_name = 'relogin_failure_kind'"
+        )
+    ).scalar()
+    if col_exists:
+        task_rows = conn.execute(
+            sa.text(
+                "SELECT id, message, relogin_failure_kind "
+                "FROM login_tasks "
+                "WHERE message IS NOT NULL AND message != ''"
+            )
+        ).fetchall()
+        for row in task_rows:
+            task_id, msg, current_kind = row[0], row[1], row[2]
+            new_kind = classify_failure(msg)
+            if new_kind and new_kind != current_kind:
+                conn.execute(
+                    sa.text(
+                        "UPDATE login_tasks SET relogin_failure_kind = :k WHERE id = :id"
+                    ),
+                    {"k": new_kind, "id": task_id},
+                )
+
+
+def downgrade() -> None:
+    pass