## ADDED Requirements

### Requirement: System prompt editor tab

The chat page SHALL include a "System Prompt" tab with a multi-line text area where the user can enter a system prompt. The system prompt value SHALL persist across tab switches within the same session.

#### Scenario: User enters a system prompt

- **WHEN** the user navigates to the System Prompt tab and types text
- **THEN** the text is stored in the component state and included in the next chat request

#### Scenario: System prompt survives tab switch

- **WHEN** the user enters a system prompt, switches to the Chat tab, then switches back
- **THEN** the system prompt text is unchanged

### Requirement: Model settings tab

The chat page SHALL include a "Model Settings" tab with controls for Temperature, TopP, and MaxTokens. Each control SHALL display its current value and allow adjustment within valid ranges.

#### Scenario: Temperature control

- **WHEN** the user adjusts the Temperature control
- **THEN** the value is constrained to 0.0–2.0 and included in the next chat request's settings

#### Scenario: TopP control

- **WHEN** the user adjusts the TopP control
- **THEN** the value is constrained to 0.0–1.0 and included in the next chat request's settings

#### Scenario: MaxTokens control

- **WHEN** the user sets the MaxTokens value
- **THEN** the value is constrained to 1–4096 and included in the next chat request's settings

#### Scenario: Default values

- **WHEN** the user has not changed any model settings
- **THEN** the controls show default values (Temperature: 1.0, TopP: 1.0, MaxTokens: empty/unset) and no overrides are sent to the API

### Requirement: Tabbed page layout

The chat page SHALL use MudTabs with three tab panels: "Chat" (the existing conversation UI), "System Prompt" (the prompt editor), and "Model Settings" (the parameter controls).

#### Scenario: Chat tab is default

- **WHEN** the page loads
- **THEN** the Chat tab is active and the conversation UI is displayed

#### Scenario: Tab switching

- **WHEN** the user clicks a different tab
- **THEN** the corresponding panel is displayed and the previous panel is hidden but retains its state