move to flakes

[arcnmx]

mostly blocked on:

• [x] https://github.com/arcnmx/flakes.nix/issues/5
• [ ] a pure revamp of tf-nix (explicit/extern imports mainly solve this)

modules that need to be migrated/revamped:

• [ ] meta
  • [ ] home: low-prio, who cares
  • [ ] repos: a single tf target really
  • [ ] archive: ties into tf and network .-.
  • [ ] deploy: tf targets
• [ ] nixos
  • [ ] deploy
  • [ ] tf: ties node to target
  • [ ] domains: certs, cert keys, and a records
  • [ ] personal: per-machine keys and secrets
  • [ ] switch: networking and node access paths
  • [ ] matrix-synapse-bridges: secrets management
  • [ ] nixbld: doesn't even work so...
  • [x] home
• [ ] home
  • [ ] deploy-home: useless shortcuts
• [ ] config
  • [ ] meta.nix: borg config