Replace flake.nix with shell.nix for simpler NixOS dev environment

flake.nix

@@ -1,21 +0,0 @@
-{
-  description = "Cohere Transcribe dev environment with microphone support";
-
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
-  };
-
-  outputs = { nixpkgs, ... }: {
-    devShells.x86_64-linux.default = nixpkgs.legacyPackages.x86_64-linux.mkShell {
-      buildInputs = with nixpkgs.legacyPackages.x86_64-linux; [
-        portaudio
-        cudaPackages.cudatoolkit
-      ];
-
-      shellHook = ''
-        export LD_LIBRARY_PATH="${cudaPackages.cudatoolkit}/lib:$LD_LIBRARY_PATH"
-        echo "Dev shell ready - microphone input enabled"
-      '';
-    };
-  };
-}

shell.nix

@@ -0,0 +1,15 @@
+{ pkgs ? import <nixpkgs> { config.allowUnfree = true; } }:
+
+pkgs.mkShell {
+  buildInputs = with pkgs; [
+    portaudio
+    cudaPackages.cudatoolkit
+    uv
+    python314
+  ];
+
+  shellHook = ''
+    export LD_LIBRARY_PATH="${pkgs.cudaPackages.cudatoolkit}/lib:$LD_LIBRARY_PATH"
+    echo "Dev shell ready - microphone input enabled"
+  '';
+}