bikeshed: Registry

[queer]

Related to #2.

While banyan is the "layers" "server" (alpine-ostree memes), we still need a consistent centralisable registry for storing binaries + layer manifests. Layer manifests are a separate concept from what's currently called a squishfile; squishfiles are a mixture of both layer manifests and information about how to run a container, currently, and ideally this should be split up.

Current thoughts:

• Split squishfile.toml into squish-app.toml and squish-manifest.toml
• Make a registry server (basically an S3 bucket?) that stores binaries + the corresponding squish-manifest.toml
• "Image tags" are immutable, and are basically just the location the "image" is uploaded to ($USER_OR_ORG/$NAME/$VERSION or smth like that)
• When booting an "image," pull its squish-manifest.toml, parse the layers, and pull all of them
• Cache layers locally to prevent re-pulls
• Treat binaries + layer manifests + layers as immutable, ie disallow overwriting an existing image (exceptions: ex. yanking from a (public?) repo?)

Challenges:

• Where the fuck do I get enough money to run a public/"primary" squish repository lmao