build: replace flake with npins, add Nix packages for web and desktop

- npins pins nixpkgs-unstable + Inter font tarball; shell.nix replaces the flake devshell
- nix/bun-deps.nix: fixed-output bun install of the workspace (hash tied to bun.lock)
- nix/web.nix: static Next.js export; next/font/google patched to local Inter for offline builds
- nix/desktop.nix: tsc-built Electron app embedding the web export, wrapped with nixpkgs electron; ffmpeg-static satisfied by nixpkgs ffmpeg

1 files changed, 11 insertions, 0 deletions

diff --git a/shell.nix b/shell.nix
new file mode 100644
index 00000000..93c79af8
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,11 @@
+let
+  sources = import ./npins;
+  pkgs = import sources.nixpkgs { };
+in
+pkgs.mkShell {
+  packages = with pkgs; [
+    bun
+    just
+    nodejs
+  ];
+}