## ADDED Requirements

### Requirement: AiRuntimeConfig schema
The system SHALL represent AI runtime settings as a shared `AiRuntimeConfig` document including at least: `version`, `updatedAt` (ISO8601), `source` (`pc` | `server`), `vendor`, `model`, `baseUrl`, `apiKey`, `prompts` (including `pdfAsk`, `videoAsk`, `audioAsk`), and `features` flags (`pdfChat`, `videoRegionAsk`, `audioClipAsk`). API keys MUST NOT be embedded in course pack zips or course manifests.

#### Scenario: Config fields present after save
- **WHEN** a parent saves AI settings on desktop StudyDeck
- **THEN** the persisted config includes vendor, model, updatedAt, prompts, features, and a stored apiKey for later sync

#### Scenario: Course pack excludes apiKey
- **WHEN** a course pack zip is built for publish
- **THEN** the pack MUST NOT contain the AI apiKey or AiRuntimeConfig secrets

### Requirement: Desktop AI settings UI
Desktop StudyDeck SHALL provide an AI settings surface to edit vendor, model, optional baseUrl, apiKey, feature prompts, and feature toggles; to save (bumping `updatedAt`); and to run a minimal connectivity test against the configured endpoint.

#### Scenario: Save bumps updatedAt
- **WHEN** the parent saves AI settings
- **THEN** `updatedAt` is set to the current time and `source` is `pc`

#### Scenario: Key masked in UI
- **WHEN** a saved apiKey exists
- **THEN** the UI MUST NOT show the full key by default (e.g. only last four characters or a password field)

#### Scenario: Test connection
- **WHEN** the parent runs “测试连接” with a valid configuration
- **THEN** the app attempts a minimal request to the configured baseUrl/model and reports success or a clear error

### Requirement: Secure desktop key storage
Desktop StudyDeck SHALL store the apiKey using OS-backed secure storage (platform keychain/credential manager) or an encrypted local fallback, and MUST NOT write the raw apiKey to world-readable plaintext logs.

#### Scenario: Key not in plaintext library JSON
- **WHEN** AI settings are saved
- **THEN** the raw apiKey is not stored in cleartext inside the ordinary library catalog JSON files