Crash from unsynchronized access to `Spotlight.instances`

[pteasima]

https://ruddarr.sentry.io/issues/5834461438/?environment=appstore&project=4506759167803392&query=is%3Aunresolved%20issue.priority%3A%5Bhigh%2C%20medium%5D&referrer=issue-stream&stream_index=1

• most likely a threading issue
• I can confirm access to that dictionary is not synchronized. I can confirm both read and writes are unsynchronized, so potential for a crash
• We should look into making Spotlight an actor (and probably at the point making instances non-static)
• Given we now know there are race conditions in the different async methods on Movies, we should thoroughly review that (Spotlight may not be the only problem)