feat(ai): Integrate OpenAI provider and enhance model config

- Add OpenAI provider implementation using @ai-sdk/openai.\n- Update `models` command/tool to display API key status for configured providers.\n- Implement model-specific `maxTokens` override logic in `config-manager.js` using `supported-models.json`.\n- Improve AI error message parsing in `ai-services-unified.js` for better clarity.

package.json

@@ -42,7 +42,7 @@
 		"@ai-sdk/azure": "^1.3.17",
 		"@ai-sdk/google": "^1.2.13",
 		"@ai-sdk/mistral": "^1.2.7",
-		"@ai-sdk/openai": "^1.3.16",
+		"@ai-sdk/openai": "^1.3.20",
 		"@ai-sdk/perplexity": "^1.1.7",
 		"@ai-sdk/xai": "^1.2.13",
 		"@anthropic-ai/sdk": "^0.39.0",