Make YouTube auth optional and non-blocking; manual stream key is baseline go-live path

TASKS.md

@@ -13,17 +13,20 @@
 
 ---
 
-## TASK 2 — YouTube OAuth2 Authentication
+## TASK 2 — YouTube OAuth2 Authentication (optional, non-blocking)
 
 **Goal:** Fully working Google OAuth2 flow — user clicks "YouTube", browser opens, authorization callback lands, channel info is stored.
 
+**Design constraint:** Sign-in must NEVER block core usage. Users can go live with a manual stream key, build scenes, and record without authenticating. OAuth is an enhancement — it unlocks live chat, broadcast creation, scheduling, and YouTube-side health — not a prerequisite.
+
 ### Requirements:
 
 1. **Google Cloud OAuth credentials** — client ID + secret (user provides; needs "Localhost" redirect URI)
 2. **Local HTTP listener** — `HttpListener` on `http://localhost:PORT/oauth2/callback` to catch the redirect
 3. **Browser launch** — open the authorization URL in the default browser
 4. **Token persistence** — store access/refresh tokens securely (Windows DPAPI), reload on startup
-5. **UI state** — account name/avatar shown when connected, connection status reflected
+5. **UI state** — account name/avatar shown when connected; "sign in (optional)" affordance, never a gate
+6. **Stream key entry stays manual** — OAuth does not replace the manual stream key path
 
 ### Tests: