Merge branch 'feature/stream-audio-mute' into collaudo

Integra il mute del microfono in diretta per il collaudo.

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

backend/db/migrate/20260812220000_add_audio_muted_to_stream_sessions.rb

@@ -0,0 +1,5 @@
+class AddAudioMutedToStreamSessions < ActiveRecord::Migration[7.2]
+  def change
+    add_column :stream_sessions, :audio_muted, :boolean, default: false, null: false
+  end
+end