fix(sync): fix sonarr/plex sync fighting over availability

fixes #872

server/job/plexsync/index.ts

@@ -543,15 +543,18 @@ class JobPlexSync {
               if (existingSeason) {
                 // These ternary statements look super confusing, but they are simply
                 // setting the status to AVAILABLE if all of a type is there, partially if some,
-                // and then not modifying the status if there are 0 items
+                // and then not modifying the status if there are 0 items.
+                // If the season was already available, we don't modify it as well.
                 existingSeason.status =
-                  totalStandard === season.episode_count
+                  totalStandard === season.episode_count ||
+                  existingSeason.status === MediaStatus.AVAILABLE
                     ? MediaStatus.AVAILABLE
                     : totalStandard > 0
                     ? MediaStatus.PARTIALLY_AVAILABLE
                     : existingSeason.status;
                 existingSeason.status4k =
-                  this.enable4kShow && total4k === season.episode_count
+                  (this.enable4kShow && total4k === season.episode_count) ||
+                  existingSeason.status4k === MediaStatus.AVAILABLE
                     ? MediaStatus.AVAILABLE
                     : this.enable4kShow && total4k > 0
                     ? MediaStatus.PARTIALLY_AVAILABLE