feat!: breaking change - OpenRouter models are now read from conf/openrouter_models.json while Custom / Self-hosted models are read from conf/custom_models.json

feat: Azure OpenAI / Azure AI Foundry support. Models should be defined in conf/azure_models.json (or a custom path). See .env.example for environment variables or see readme. https://github.com/BeehiveInnovations/zen-mcp-server/issues/265

feat: OpenRouter / Custom Models / Azure can separately also use custom config paths now (see .env.example )

refactor: Model registry class made abstract, OpenRouter / Custom Provider / Azure OpenAI now subclass these

refactor: breaking change: `is_custom` property has been removed from model_capabilities.py (and thus custom_models.json) given each models are now read from separate configuration files

docs/model_ranking.md

@@ -25,7 +25,7 @@ feature_bonus = (
     + (1 if supports_json_mode else 0)
     + (1 if supports_images else 0)
 )
-penalty = 1 if is_custom else 0
+penalty = 1 if provider == CUSTOM else 0
 
 effective_rank = clamp(base + ctx_bonus + output_bonus + feature_bonus - penalty, 0, 100)
 ```