Risolve timeout creazione sessione YouTube lato app.

La setup broadcast YouTube (~23s) passa in background job; l'API risponde
subito. Aumentato anche il timeout Dio mobile per createSession YouTube.

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

backend/app/services/youtube/setup_broadcast.rb

@@ -0,0 +1,52 @@
+module Youtube
+  # Crea broadcast/stream YouTube e avvia relay (operazione lenta, ~20s).
+  class SetupBroadcast
+    class Error < StandardError; end
+
+    def self.call(session, youtube_channel: nil)
+      new(session, youtube_channel: youtube_channel).call
+    end
+
+    def initialize(session, youtube_channel: nil)
+      @session = session
+      @youtube_channel = youtube_channel
+    end
+
+    def call
+      @session.reload
+      return @session if @session.terminal?
+      return @session if @session.platform != "youtube"
+      return @session if @session.youtube_broadcast_id.present?
+
+      yt = BroadcastService.new(@session.match.team, channel: @youtube_channel)
+      title = "#{@session.match.team.name} vs #{@session.match.opponent_name}"
+      broadcast = yt.create_broadcast!(
+        title: title,
+        privacy_status: @session.privacy_status,
+        scheduled_at: @session.match.scheduled_at
+      )
+
+      @session.update!(
+        youtube_broadcast_id: broadcast[:broadcast_id],
+        youtube_stream_id: broadcast[:stream_id],
+        stream_key: broadcast[:stream_key],
+        rtmp_url: broadcast[:rtmp_url]
+      )
+
+      Streams::YoutubeRelay.start(@session)
+      @session.stream_events.create!(
+        event_type: "youtube_ready",
+        metadata: { broadcast_id: broadcast[:broadcast_id] },
+        occurred_at: Time.current
+      )
+      @session
+    rescue BroadcastService::Error => e
+      @session.stream_events.create!(
+        event_type: "error",
+        metadata: { source: "youtube_setup", message: e.message },
+        occurred_at: Time.current
+      )
+      raise Error, e.message
+    end
+  end
+end