fix: The "tags" lack the key words related to the memory content.

[whipser030]

Description

Please include a summary of the change, the problem it solves, the implementation approach, and relevant context. List any dependencies required for this change.

Related Issue (Required): Fixes #998

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (does not change functionality, e.g. code style improvements, linting)
• Documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Unit Test
• Test Script Or Test Steps (please provide)
• Pipeline Automated API Test (please provide)

Test Script:
step1: Insert a line of code at line 741, to simulate the situation where a large model fails to be invoked: ./src/memos/mem_reader/read_multi_modal/file_content_parser.py

step2: Start the local service and run the following add request
curl --location --request POST 'http://127.0.0.1:8002/product/add'
--header 'Content-Type: application/json'
--data-raw '{
"user_id": "testfile_0202",
"mem_cube_id": "testfile_0202_cube",
"async_mode" : "sync",
"messages": [
{
"file": {
"file_data": "https://memos-file.oss-cn-shanghai.aliyuncs.com/algorithm/2026/01/13/0544a5cae26f4975b056b4738f34d7da.md",
"file_id": "0544a5cae26f4975b056b4738f34d7da",
"filename": "rick.txt"
},
"type": "file"
}
],
"info":{"source_type":"extreme_multimodal"}
}'

step3：Initiate a search request
curl --location --request POST 'http://127.0.0.1:8002/product/search'
--header 'Content-Type: application/json'
--data-raw '{
"user_id": "testfile_0202",
"readable_cube_ids": ["testfile_0202_cube"],
"query": "minddock",
"top_k":20
}'

step4: Check whether the tags of each item in the recall results contain any words related to the memory topic.

As shown in the example, in the case where the large model fails to access, the tags still retain the relevant words for proposing.

step5: Don't forget to restore the code after the test is completed.

Checklist

• I have performed a self-review of my own code | 我已自行检查了自己的代码
• I have commented my code in hard-to-understand areas | 我已在难以理解的地方对代码进行了注释
• I have added tests that prove my fix is effective or that my feature works | 我已添加测试以证明我的修复有效或功能正常
• I have created related documentation issue/PR in MemOS-Docs (if applicable) | 我已在 MemOS-Docs 中创建了相关的文档 issue/PR（如果适用）
• I have linked the issue to this PR (if applicable) | 我已将 issue 链接到此 PR（如果适用）
• I have mentioned the person who will review this PR | 我已提及将审查此 PR 的人

Reviewer Checklist

• closes #xxxx (Replace xxxx with the GitHub issue number)
• Made sure Checks passed
• Tests have been provided