Add Poe provider support

[kamilio]

Summary

• add Poe as a first-class provider/endpoint in shared config enums, fetch token map, and UI metadata
• surface Poe-specific icon asset plus example configuration to help users wire it up quickly
• ensure Poe behaves like other custom providers (MCP parser/types, agent runtime, endpoint config) and add targeted tests for the new path

Change Type

• New feature (non-breaking change which adds functionality)

Testing

• cd api && npx jest server/services/Endpoints/index.spec.js
• ran docker locally and test out the integration with Poe API

Test Configuration:

• Node 18

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• I have written tests demonstrating that my changes are effective or that my feature works
• Local unit tests pass with my changes