chore: build premiere_timestamp using video_type and published time

src/invidious/routes/watch.cr

@@ -129,6 +129,8 @@ module Invidious::Routes::Watch
     video_streams = video.video_streams
     audio_streams = video.audio_streams
 
+    # Videos that are a premiere do not have audio streams.
+    if video.premiere_timestamp.nil?
       # Older videos may not have audio sources available.
       # We redirect here so they're not unplayable
       if audio_streams.empty? && !video.live_now
@@ -142,6 +144,7 @@ module Invidious::Routes::Watch
           return env.redirect "/watch?#{env.params.query}"
         end
       end
+    end
 
     captions = video.captions
 

src/invidious/videos.cr

@@ -81,10 +81,11 @@ struct Video
   end
 
   def premiere_timestamp : Time?
-    info
-      .dig?("microformat", "playerMicroformatRenderer", "liveBroadcastDetails", "startTimestamp")
+    if self.video_type == VideoType::Scheduled
+      return info["published"]?
         .try { |t| Time.parse_rfc3339(t.as_s) }
     end
+  end
 
   def related_videos
     info["relatedVideos"]?.try &.as_a.map { |h| h.as_h.transform_values &.as_s } || [] of Hash(String, String)