Use the `Accept-Language header` to switch the language when first opening the web UI of `dbeaver/cloudbeaver`

**Is your feature request related to a problem? Please describe.**
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- No.

**Describe the solution you'd like**
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- Use the `Accept-Language header` to switch the language when first opening the web UI of `dbeaver/cloudbeaver`. See https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Accept-Language .
- If a user executes the following command in Ubuntu WSL 26.04,
```bash
docker pull gh-proxy.org/docker/dbeaver/cloudbeaver:26.1.5
docker tag gh-proxy.org/docker/dbeaver/cloudbeaver:26.1.5 dbeaver/cloudbeaver:26.1.5

tee ./cloudbeaver.yaml <
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- If we could check https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Accept-Language to switch languages ​​when the webpage is first opened, it would obviously avoid the embarrassment for some people who don't understand English.

**Describe alternatives you've considered**
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- To be honest, I don't think there's a more reasonable solution than `Accept-Language header`. Some external discussions surrounding browser standards can be found at https://x.com/iseki_zero/status/2091304187896508449?s=20 .

**Additional context**
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- Null.

Start by tracing the web UI's language initialization and checking how supported locales are selected when the application first loads. Reproduce the report in Microsoft Edge with Simplified Chinese and verify that the initial interface language follows the browser's Accept-Language header while manual language selection continues to work.

Written by the indexing model from the issue text.