docs: translate API reference pages

[RerankerGuo]

Description

Fixes #1695.

Adds English translations for the remaining setup, scheduler, tools, and error-code API reference pages under docs/en/open_source/open_source_api/.

The scheduler wait page uses the clean scheduler/wait.md path, and the overview page uses corrected relative links from the start/ directory.

Related Issue (Required): Fixes #1695

Type of change

• 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?

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

Commands run:

for p in docs/en/open_source/open_source_api/start/configuration.md docs/en/open_source/open_source_api/start/overview.md docs/en/open_source/open_source_api/scheduler/get_status.md docs/en/open_source/open_source_api/scheduler/wait.md docs/en/open_source/open_source_api/tools/check_cube.md docs/en/open_source/open_source_api/tools/get_user_names.md docs/en/open_source/open_source_api/help/error_codes.md; do test -s "$p" && printf 'ok %s\n' "$p" || printf 'missing-or-empty %s\n' "$p"; done

test ! -e 'docs/en/open_source/open_source_api/scheduler/ wait.md' && echo 'clean scheduler wait path ok'
rg -n '\]\(\./(core|chat|message|scheduler|tools|help)/' docs/en/open_source/open_source_api/start docs/en/open_source/open_source_api/scheduler docs/en/open_source/open_source_api/tools docs/en/open_source/open_source_api/help || true
make format

Results:

• All seven target files exist and are non-empty.
• The scheduler page exists as scheduler/wait.md; no leading-space filename was created.
• The broken ./core, ./chat, ./message, ./scheduler, ./tools, or ./help links were not found.
• make format is blocked locally because poetry is not installed (make: poetry: Command not found).

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 Translate setup, scheduler, tools, and error API docs to English #1695
• Made sure Checks passed
• Tests have been provided