Manager approval 1b1bcca added `pkgs.prefetch-npm-deps` to my
container. Ran `prefetch-npm-deps frontend/package-lock.json` →
`sha256-MHXxkZpe/5LAhpQ76ZK94znG2noTobthjUi6iNY8/K4=`. Replaced
the `lib.fakeHash` placeholder in `nix/frontend.nix` with the real
value; updated the comment to point at the recompute command instead
of the let-it-fail workflow.
This unblocks PR #350 for merge — `nix build .#frontend` will now
succeed without the operator having to compute and patch the hash.
Refs #273.
0e2319d206