Add advanced configuration tools for power users

[jeffpaul]

Description

Provide configuration options and tools that give advanced users more control over AI behavior and provider usage. These should be opt-in and surfaced in a way that does not overwhelm non-technical users.

Goals

• Extend settings UI to include an “Advanced” tab or expandable section.
• Add configuration controls for: Model selection or override (where supported by the provider).
• Add configuration controls for: Adjustable model parameters such as temperature, top_p, and max tokens.
• Add configuration controls for: Logging or debug mode toggle.
• Integrate these options into the AI Playground where relevant to reduce duplication.
• Document how these advanced settings affect provider behavior and plugin performance.

Acceptance Criteria

• Advanced configuration UI appears only when experimental features are enabled.
• Settings persist and are accessible to feature modules.
• Non-technical users are not exposed to unnecessary complexity.
• Documentation updated to explain each option and its purpose.