Integrazione YouTube Live: OAuth squadra, canale piattaforma Light e UI.

Collegamento da Dettagli squadra e admin per il refresh token Match Live TV; API e app mobile allineate ai piani Light/Full.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/controllers/admin/youtube_controller.rb

@@ -0,0 +1,13 @@
+module Admin
+  class YoutubeController < Admin::BaseController
+    def platform
+      if ENV["YOUTUBE_CLIENT_ID"].blank?
+        redirect_to admin_root_path, alert: "Configura YOUTUBE_CLIENT_ID e YOUTUBE_CLIENT_SECRET in .env"
+        return
+      end
+
+      state = Youtube::OauthState.for_platform(admin_id: current_admin_account.id)
+      redirect_to Youtube::OauthUrl.build(state: state), allow_other_host: true
+    end
+  end
+end