chore: improve Nix flake

flake.nix

@@ -2,33 +2,38 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     flake-utils.url = "github:numtide/flake-utils";
+    pre-commit-hooks = {
+      url = "github:cachix/git-hooks.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs =
-    { nixpkgs
+    { self
+    , nixpkgs
     , flake-utils
     , ...
-    }:
+    }@inputs:
     flake-utils.lib.eachDefaultSystem (system:
     let
       pkgs = import nixpkgs {
         inherit system;
       };
-    in
-    {
-      devShells.default = pkgs.mkShell {
-        name = "immich-tools";
-        buildInputs = with pkgs; [
+      # Place all toolchain components in a single directory for IntelliJ
+      rust-toolchain = pkgs.symlinkJoin {
+        name = "rust-toolchain";
+        paths = with pkgs; [
+          rustc
           cargo
-          cargo-machete
-          cargo-release
-          cargo-sort
-          openssl
-          pkg-config
+          rustPlatform.rustcSrc
         ] ++ lib.optionals stdenv.isDarwin [
           libiconv
-          darwin.apple_sdk.frameworks.SystemConfiguration
         ];
       };
+    in
+    {
+      checks = import ./nix/git-hooks.nix { inherit inputs pkgs; };
+      devShells = import ./nix/shell.nix { inherit pkgs rust-toolchain self; };
+      formatter = pkgs.nixpkgs-fmt;
     });
 }