fix: Add missing default_mode field to DSSeekConfig dataclass

[Copilot]

Uploading docx files failed with DSSeekConfig.__init__() got an unexpected keyword argument 'default_mode'. The DSSeekConfig dataclass was missing the default_mode field that api/insert.py passes when creating the DeepSeek-OCR client with tenant configuration.

Changes

• Added default_mode field to DSSeekConfig in src/deepseek_ocr_client.py

# OCR 模式配置
default_mode: str = field(default_factory=lambda: config.ds_ocr.default_mode)

Note on TXT file URL issue

The reported TXT file URL issue is a configuration problem, not a code bug. TXT files are read directly and don't use remote parsing services. Users experiencing URL issues should verify their FILE_SERVICE_BASE_URL environment variable.

Original prompt

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This section details on the original issue you should resolve

<issue_title>api</issue_title>
<issue_description>first i tried to upload docx,died because
Unexpected error: DSSeekConfig.init() got an unexpected keyword argument 'default_mode';
second i tried to upload txt,seems like it dosent get a right url ,its my env file.

.env.txt</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes api #3

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[BukeLy]

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