docs: list v0.5 among the released versions in the readme

[poppycoderr]

Background

The roadmap summary in the README still listed multi-tenancy as upcoming work. It shipped in v0.5.0.

Changes

• Both READMEs list v0.5 under the released versions and drop multi-tenancy from the upcoming items.

+5. **v0.5 Operator context**: audit fields and fail-closed multi-tenancy ..., ArchGuard fix hints in English
 Next:
-5. **More integrations**: Elasticsearch read models, MyBatis-Plus multi-tenancy and data permissions, ...
+6. **More integrations**: Elasticsearch read models, data permissions, ...

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背景

README 里的路线图摘要还把多租户列在待做事项里，它已经随 v0.5.0 发布。

改动

• 中英文 README 把 v0.5 列入已发布版本，并从待做事项里去掉多租户（见上文 diff）。