thumbnail/image caching

[crccheck]

options:

• service worker caching - fast, but server still has to serve a lot of requests. that doesn't matter though since this is just a personal app
• nginx caching - makes deploy complicated
• redis caching - makes deploy and code complicated
• sqlite cache - would open up a lot of other possibilities but makes the code way complicated

[crccheck]

service worker isn't working out

1. Something in Snowpack's dev build injects import statements that break the JavaScript file
2. Reloading the service worker sucks

Now i'm thinking of doing a local filesystem cache like I had originally. It would work as a static file handler falling back to the thumbs handler. I sure hope you can have two url routes serving the same urls. We'd get automatic 304 not-modified responses and PIL is just used to working with files.

I'm thinking all the thumbs are in one directory and the filename is a hash of the path