initial app add

Signed-off-by: ahuston-0 <aliceghuston@gmail.com>

shell.nix

@@ -0,0 +1,49 @@
+{
+  self,
+  inputs,
+  checks,
+  system,
+  ...
+}:
+
+  let
+    inherit (inputs) nixpkgs;
+    pkgs = nixpkgs.legacyPackages.${system};
+
+    # construct the shell provided by pre-commit for running hooks
+    pre-commit = pkgs.mkShell {
+      inherit (checks.pre-commit-check) shellHook;
+      buildInputs = checks.pre-commit-check.enabledPackages;
+    };
+
+    # constructs a custom shell with commonly used utilities
+    rad-dev = pkgs.mkShell {
+      packages = with pkgs; [
+        deadnix
+        pre-commit
+        treefmt
+        statix
+        nixfmt-rfc-style
+      ];
+    };
+
+    # constructs the application in-place
+    app = pkgs.mkShell{
+      inputsFrom = [self.packages.${system}.myapp];
+    };
+
+    # pull in python/poetry dependencies
+    poetry = pkgs.mkShell {
+      pacakges = [pkgs.poetry];
+    };
+  in
+  {
+    default = pkgs.mkShell {
+      inputsFrom = [
+        pre-commit
+        rad-dev
+        app
+        poetry
+      ];
+    };
+  }