feature: add domainMapping in config, to allow for localModels

[mihaisavezi]

No description provided.

[mihaisavezi]

fixes #4

🗺️ Add Configuration-Based Domain Mappings Feature
Problem Solved
Issue: Local model servers (localhost, 127.0.0.1) couldn't be used because of hardcoded domain mappings in the provider registry

Error: API Error: 400 provider not found: no provider implementation for domain: localhost

Root Cause: The registry only supported predefined domains (api.openai.com, openrouter.ai, etc.)

Solution Implemented

1. Configuration Structure Enhancement
   Added DomainMappings map[string]string field to Config struct

Supports YAML configuration format:

# Route local LM Studio to use OpenAI transformations
domain_mappings:
  localhost: openai

providers:
  - name: local-lmstudio
    url: "http://localhost:1234/v1/chat/completions"
    api_key: "not-needed"

router:
  default: "local-lmstudio,qwen/qwen3-coder-30b"

2. Provider Registry Updates
   Enhanced Registry struct with dynamic domain mapping support

Added SetDomainMappings() method to accept config-based mappings

Modified GetByDomain() to check config mappings first, then fall back to hardcoded mappings

Priority System: Configuration mappings override hardcoded ones

3. Server Integration
   Updated server initialization to pass domain mappings from config to registry

Automatic configuration loading and application on startup

4. Command Line Interface Enhancements
   cco config show:

Now displays Domain Mappings section

Shows configured domain → provider mappings

cco config validate:

Validates that mapped providers exist (both configured and built-in)

Provides detailed error messages for invalid mappings

cco config generate:

Includes domain mappings in example configuration

Provides local model setup examples

5. Testing Infrastructure
   Added comprehensive unit tests for YAML parsing

Registry integration tests for domain mapping functionality

Configuration command tests

Fixed test expectations to account for new local-lmstudio provider

# Route local LM Studio to use OpenAI transformations
domain_mappings:
  localhost: openai

providers:
  - name: local-lmstudio
    url: "http://localhost:1234/v1/chat/completions"
    api_key: "not-needed"

router:
  default: "local-lmstudio,qwen/qwen3-coder-30b"

[Davincible]

Thanks for the contributions!