feat: add multi-provider authentication and inference provider selection

- Implemented a multi-provider authentication system for the Hermes Agent, supporting OAuth for Nous Portal and traditional API key methods for OpenRouter and custom endpoints.
- Enhanced CLI with commands for logging in and out of providers, allowing users to authenticate and manage their credentials easily.
- Updated configuration options to select inference providers, with detailed documentation on usage and setup.
- Improved status reporting to include authentication status and provider details, enhancing user awareness of their current configuration.
- Added new files for authentication handling and updated existing components to integrate the new provider system.

cli-config.yaml.example

@@ -9,6 +9,13 @@ model:
   # Default model to use (can be overridden with --model flag)
   default: "anthropic/claude-opus-4.6"
   
+  # Inference provider selection:
+  #   "auto"       - Use Nous Portal if logged in, otherwise OpenRouter/env vars (default)
+  #   "openrouter" - Always use OpenRouter API key from OPENROUTER_API_KEY
+  #   "nous"       - Always use Nous Portal (requires: hermes login)
+  # Can also be overridden with --provider flag or HERMES_INFERENCE_PROVIDER env var.
+  provider: "auto"
+  
   # API configuration (falls back to OPENROUTER_API_KEY env var)
   # api_key: "your-key-here"  # Uncomment to set here instead of .env
   base_url: "https://openrouter.ai/api/v1"