Class: AiClient  - X-Ref

Main AI Client class providing both fluent and traditional APIs for AI operations.

This class serves as the primary entry point for AI operations, offering:
- Fluent API for easy-to-read chained method calls
- Traditional API for array-based configuration (WordPress style)
- Integration with provider registry for model discovery
- Support for three model specification approaches

All model requirements analysis and capability matching is handled
automatically by the PromptBuilder, which provides intelligent model
discovery based on prompt content and configuration.

## Model Specification Approaches

### 1. Specific Model Instance
Use a specific ModelInterface instance when you know exactly which model to use:
```php
$model = $registry->getProvider('openai')->getModel('gpt-4');
$result = AiClient::generateTextResult('What is PHP?', $model);
```

### 2. ModelConfig for Auto-Discovery
Use ModelConfig to specify requirements and let the system discover the best model:
```php
$config = new ModelConfig();
$config->setTemperature(0.7);
$config->setMaxTokens(150);

$result = AiClient::generateTextResult('What is PHP?', $config);
```

### 3. Automatic Discovery (Default)
Pass null or omit the parameter for intelligent model discovery based on prompt content:
```php
// System analyzes prompt and selects appropriate model automatically
$result = AiClient::generateTextResult('What is PHP?');
$imageResult = AiClient::generateImageResult('A sunset over mountains');
```

## Fluent API Examples
```php
// Fluent API with automatic model discovery
$result = AiClient::prompt('Generate an image of a sunset')
->usingTemperature(0.7)
->generateImageResult();

// Fluent API with specific model
$result = AiClient::prompt('What is PHP?')
->usingModel($specificModel)
->usingTemperature(0.5)
->generateTextResult();

// Fluent API with model configuration
$result = AiClient::prompt('Explain quantum physics')
->usingModelConfig($config)
->generateTextResult();
```