Set up devenv to use nix

.gitignore

@@ -24,3 +24,5 @@ open_ai_client-*.tar
 
 # Temporary files, for example, from tests.
 /tmp/
+.nix-hex
+.nix-mix

.zellij.kdl

@@ -0,0 +1,32 @@
+layout {
+	default_tab_template split_direction="horizontal" {
+		children
+		pane size=1 borderless=true {
+			plugin location="compact-bar"
+		}
+	}
+
+	tab name="1 code" focus=true {
+		pane split_direction="vertical" {
+			pane name="editor" size="80%" focus=true command="nvim" borderless=true
+			pane name="tests" size="20%" command="mix" {
+				args "test.interactive" "--stale"
+			}
+		}
+	}
+
+	// tab name="2 servers" {
+	// 	pane split_direction="vertical" {
+	// 		pane name="docker" command="docker" { 
+	// 			args "compose" "up"
+	// 		}
+	// 		pane name="web" command="iex" start_suspended=true {
+	// 			args "-S" "mix" "phx.server"
+	// 		}
+	// 	}
+	// }
+
+	tab name="2 git" {
+		pane name="git" command="lazygit" borderless=true
+	} 
+}

flake.nix

@@ -0,0 +1,57 @@
+{
+  description = "A flake for building development environment of Phoenix project.";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/master";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      with pkgs; {
+        devShells.default = mkShell {
+          buildInputs = [
+            beam.interpreters.erlang_27
+            beam.packages.erlang_27.elixir_1_16
+            nodePackages.nodejs
+            flyctl
+          ]
+          ++ lib.optionals stdenv.isLinux [
+            # For ExUnit Notifier on Linux.
+            libnotify
+
+            # For file_system on Linux.
+            inotify-tools
+          ]
+          ++ lib.optionals stdenv.isDarwin [
+            # For ExUnit Notifier on macOS.
+            terminal-notifier
+
+            # For file_system on macOS.
+            darwin.apple_sdk.frameworks.CoreFoundation
+            darwin.apple_sdk.frameworks.CoreServices
+          ];
+
+          shellHook = ''
+            # allows mix to work on the local directory
+            mkdir -p .nix-mix
+            mkdir -p .nix-hex
+            export MIX_HOME=$PWD/.nix-mix
+            export HEX_HOME=$PWD/.nix-hex
+            export ERL_LIBS=$HEX_HOME/lib/erlang/lib
+
+            # concats PATH
+            export PATH=$MIX_HOME/bin:$PATH
+            export PATH=$MIX_HOME/escripts:$PATH
+            export PATH=$HEX_HOME/bin:$PATH
+
+            # enables history for IEx
+            export ERL_AFLAGS="-kernel shell_history enabled -kernel shell_history_path '\"$PWD/.erlang-history\"'"
+          '';
+        };
+      }
+    );
+}