The credential pool seeder (_seed_from_env) hardcoded the base URL
for API-key providers without running provider-specific auto-detection.
For kimi-coding, this caused sk-kimi- prefixed keys to be seeded with
the legacy api.moonshot.ai/v1 endpoint instead of api.kimi.com/coding/v1,
resulting in HTTP 401 on the first request.
Import and call _resolve_kimi_base_url for kimi-coding so the pool
uses the correct endpoint based on the key prefix, matching the
runtime credential resolver behavior.
Also fix a comment: sk-kimi- keys are issued by kimi.com/code,
not platform.kimi.ai.
Fixes#5561
4d1b988070