[Improvement] Allow unauthenticated access to /api/version endpoint

## What would you like to be improved?

The `/api/version` endpoint currently requires authentication. Accessing it without credentials returns a 401 `UnauthorizedException`:

```
curl http://:8090/api/version
{"code":1011,"type":"UnauthorizedException","message":"The provided credentials did not support",...}
```

The version endpoint is a purely informational, read-only API that exposes no sensitive data. Requiring authentication creates unnecessary friction for:
- Operators checking server version during deployment/upgrades
- Health monitoring tools and scripts that don't need full credentials
- Client compatibility checks before establishing an authenticated session

By contrast, the `/health` endpoint already bypasses authentication (via `HealthCheckPathMatcher`), so there is an established pattern to follow.

## How should we improve?

Extend the authentication bypass in `AuthenticationFilter` (or `HealthCheckPathMatcher`) to also skip authentication for `GET /api/version`, similar to how health check paths are handled today.

Read AuthenticationFilter and HealthCheckPathMatcher to trace how /health bypasses authentication. Add the same handling for GET /api/version, then verify that an unauthenticated request returns the version response while other protected endpoints still require credentials.

Written by the indexing model from the issue text.