### What problem does this PR solve?
api_host -> webAPI
ExternalApi -> restAPIv1
### Type of change
- [x] Refactoring
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Refactor**
* Updated internal API endpoint configuration to use consolidated base
URL constants for improved maintainability and consistency across the
application.
* **Chores**
* Updated server-side protocol validation for admin connectivity checks.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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Signed-off-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
Now user can use 'think mode' to chat with LLM
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
As title.
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
- [x] Refactoring
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>