Also changes the schemas a bit (still don't care about migrations),
switches to named_params!, fixes up perf issues when ingesting manifests
and/or hrefs into sqlite, etc. Adds sample queries such as "CudaArtifact
conflicts" to datasette config, which explain some issues associated
with choosing an evalModules schema on the cudaPackages side.
First attempt at both Rust and snix-castore.
I'll start by putting together a single-file CLI app,
no splitting modules out until needed, no separation of concerns.
Currently, just the fetching is implemented:
```
$ sidx pkgs/dev*/cuda-*/cuda/manifests/*.json
```
npins: init
