Services — index

External-facing logic: YouTube API, persistence. See schema.md for the memory-map conventions.

File	Purpose
`YouTubeAuthService.cs`	OAuth2 via Google: loopback callback (`http://localhost:8765/oauth2/callback`), token exchange, refresh, channel fetch. Constructor takes optional `HttpClient` + `sessionChanged` callback (test seam + save hook); session persists via `Helpers/TokenStore` (DPAPI)
`YouTubeStreamService.cs`	Broadcast/stream management via the v3 API (`enableAutoStart/Stop`). Not yet switched to the `variable` reusable stream
`YouTubeChatService.cs`	Polls `liveChat/messages`, raises `MessageReceived`; `IDisposable`
`LayoutStore.cs`	SQLite persistence (`Microsoft.Data.Sqlite`) at `%APPDATA%\ytLlive\ytLlive.db`; assets stored as BLOBs keyed by SHA-256 content hash; save/open layout files

Related: constructed in ViewModels/MainViewModel.cs (no DI container yet). Models in Models/index.md. OAuth credentials live in Helpers/OAuthCredentials.cs.