Add Nix package, NixOS module, and tests for bambuddy
- packages.bambuddy: FastAPI backend + prebuilt React frontend assembled
into the app-root layout upstream expects, behind a single `bambuddy`
launcher (uvicorn --loop asyncio, ffmpeg on PATH, XDG state defaults).
Pins upstream maziggy/bambuddy v1.2.5.7.
- nixosModules.default: services.bambuddy with host/port/dataDir,
openFirewall, environment + environmentFile, extraPackages,
DynamicUser + StateDirectory, systemd hardening, and
CAP_NET_BIND_SERVICE for the virtual-printer FTPS/RTSP ports.
- checks.bambuddy-import: backend import + admin CLI smoke test.
- checks.bambuddy-service: two-node NixOS VM test covering the health
endpoint, UI/static assets/manifest, SQLite + logs in the
StateDirectory, journal startup check, cross-node reachability with
openFirewall, custom host/port/env node, and loopback-only binding.
- overlay, run app, devShell, README, .gitignore.