* Providers: set default Kimi coding user agent
* Tests: cover Kimi coding header overrides
* Changelog: note Kimi coding user agent
* Tests: satisfy Kimi provider fixture type
* Update CHANGELOG.md
* Providers: preserve Kimi headers through models merge
* fix(providers): respect user-configured baseUrl for kimi-coding
The kimi-coding provider was built exclusively from
`buildKimiCodingProvider()` defaults, ignoring any user-specified
`baseUrl` or other overrides in `openclaw.json` providers config.
This caused 404 errors when users configured a custom endpoint.
Now merge `explicitProviders["kimi-coding"]` on top of defaults,
matching the pattern used by ollama/vllm. User's `baseUrl`, `api`,
and `models` take precedence; env/profile API key still wins.
Fixes#36353
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* Tests: use Kimi implicit provider harness
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Vincent Koc <vincentkoc@ieee.org>