hermes - 💡(How to fix) Fix doctor should honor provider base URL overrides for Xiaomi health checks [2 pull requests]

Bug Description

hermes doctor can report a valid Xiaomi MiMo key as invalid when the key is meant to be used with a regional Xiaomi endpoint configured via XIAOMI_BASE_URL.

There is also a smaller summary issue: optional toolsets such as discord_admin can warn about missing optional credentials, but still contribute to the top-level "Run 'hermes setup' to configure missing API keys for full tool access" issue.

Steps to Reproduce

1. Configure Xiaomi credentials with a regional endpoint:

   XIAOMI_API_KEY=<valid regional key>
   XIAOMI_BASE_URL=https://token-plan-cn.xiaomimimo.com/v1

2. Run:

   hermes doctor

3. Leave optional integrations like Discord unconfigured.

Expected Behavior

• Doctor should validate Xiaomi using the same base URL Hermes uses at runtime (XIAOMI_BASE_URL when set).
• Optional integration credentials such as DISCORD_BOT_TOKEN should be shown as warnings, but should not fail the summary for users who do not use those integrations.

Actual Behavior

• Doctor may probe the default Xiaomi models endpoint instead of the configured regional base URL, causing a valid regional key to be reported as invalid.
• Optional discord_admin missing credentials can contribute to the top-level setup issue.

Notes

The dynamic ProviderProfile path separates API-key env vars from base-URL env vars by inspecting ProviderProfile.env_vars. The Xiaomi profile only declares XIAOMI_API_KEY; its XIAOMI_BASE_URL metadata lives in the auth/provider registries. As a result, doctor can miss the base URL override even though runtime provider resolution uses it correctly.