Fix hub diretta: considera solo l'ultima sessione, non idle orfane.

Dopo «Termina trasmissione» la partita restava visibile se esisteva una vecchia sessione idle precedente a quella ended; l'hub e l'app usano ora lo stato dell'ultima sessione.

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

backend/app/controllers/api/v1/matches_controller.rb

@@ -130,9 +130,7 @@ module Api
       end
 
       def active_session_for(match)
-        match.stream_sessions
-             .order(created_at: :desc)
-             .find { |s| !%w[ended error].include?(s.status) }
+        match.active_stream_session
       end
     end
   end

backend/app/controllers/public/matches_controller.rb

@@ -94,9 +94,7 @@ module Public
     end
 
     def active_session_for(match)
-      match.stream_sessions
-           .order(created_at: :desc)
-           .find { |s| !%w[ended error].include?(s.status) }
+      match.active_stream_session
     end
   end
 end

backend/app/models/match.rb

@@ -34,8 +34,10 @@ class Match < ApplicationRecord
   end
 
   def active_stream_session
-    stream_sessions.sort_by { |s| s.created_at }.reverse
-      .find { |s| !%w[ended error].include?(s.status) }
+    latest = stream_sessions.max_by(&:created_at)
+    return nil if latest.nil? || latest.status.in?(%w[ended error])
+
+    latest
   end
 
   def deletable?