Implementa pausa diretta con copertina slate e ripresa.

Metti in pausa ferma RTMP lato app mantenendo la camera aperta, MediaMTX
manda offline.mp4 agli spettatori e Chiudi termina definitivamente.

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

backend/app/services/mediamtx/client.rb

@@ -18,6 +18,9 @@ module Mediamtx
       body = {
         source: "publisher",
         overridePublisher: true,
+        alwaysAvailable: true,
+        alwaysAvailableFile: slate_file_path,
+        alwaysAvailableTracks: slate_tracks,
         record: record,
         recordPath: "/recordings/%path/%Y-%m-%d_%H-%M-%S",
         recordSegmentDuration: "60s"
@@ -43,6 +46,21 @@ module Mediamtx
       @conn.post("/v3/config/paths/delete/#{CGI.escape(path_name)}")
     end
 
+    def patch_path(session)
+      path = session.mediamtx_path_name
+      body = {
+        alwaysAvailable: true,
+        alwaysAvailableFile: slate_file_path,
+        alwaysAvailableTracks: slate_tracks
+      }
+      response = @conn.patch("/v3/config/paths/patch/#{CGI.escape(path)}", body)
+      unless response.success?
+        err = response.body.is_a?(Hash) ? response.body["error"] : response.body
+        raise Error, "MediaMTX path patch failed: #{response.status} #{err}"
+      end
+      true
+    end
+
     def list_paths
       response = @conn.get("/v3/paths/list")
       return [] unless response.success?
@@ -87,7 +105,6 @@ module Mediamtx
     end
 
     def relay_script(session)
-      return "echo 'no youtube key'" if session.stream_key.blank?
       return "echo 'youtube relay skipped'" unless session.platform == "youtube"
 
       key = session.stream_key
@@ -97,5 +114,16 @@ module Mediamtx
         rtmp://a.rtmp.youtube.com/live2/#{key} 2>/var/log/ffmpeg-#{path}.log
       SCRIPT
     end
+
+    def slate_file_path
+      ENV.fetch("MEDIAMTX_SLATE_FILE", "/slates/offline.mp4")
+    end
+
+    def slate_tracks
+      [
+        { codec: "H264" },
+        { codec: "MPEG4Audio", sampleRate: 48_000, channelCount: 2 }
+      ]
+    end
   end
 end