feat: Make AI engine parameters (temperature, num_ctx) configurable

[dguembel-itomig]

Problem

Currently, AI engine parameters like temperature and num_ctx are hardcoded in OllamaAIEngine.php:

$oConfig->modelOptions = array(
    'num_ctx' => '16384',
    'temperature' => '0.4',
);

This is not ideal because:

• temperature is a parameter supported by all AI providers — it should be configurable across engines
• num_ctx (context window size) is Ollama-specific and may not apply to other providers
• Users cannot adjust these values without modifying the source code

Proposed Solution

Make these parameters configurable via iTop's configuration system, e.g. through ai_engine.configuration.model_options:

'ai_engine.configuration' => array(
    'url' => 'http://127.0.0.1:11434/api/',
    'api_key' => '',
    'model' => 'qwen2.5:14b',
    'model_options' => array(
        'temperature' => '0.4',
        'num_ctx' => '16384',
    ),
),

Each engine implementation could then read and apply relevant options from this configuration.

Scope

• Concrete: OllamaAIEngine — currently the only engine with hardcoded model options (removed in v26.1.1)
• General: All engines could benefit from a standardized way to pass provider-specific parameters

Notes

In v26.1.1, the hardcoded model_options block has been removed from OllamaAIEngine as a cleanup step. This issue tracks the follow-up work to make these parameters properly configurable.