Add formatter

flake.lock

@@ -549,6 +549,22 @@
         "type": "github"
       }
     },
+    "nixpkgs_4": {
+      "locked": {
+        "lastModified": 1726871744,
+        "narHash": "sha256-V5LpfdHyQkUF7RfOaDPrZDP+oqz88lTJrMT1+stXNwo=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "a1d92660c6b3b7c26fb883500a80ea9d33321be2",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "nur": {
       "locked": {
         "lastModified": 1729855863,
@@ -608,7 +624,8 @@
         "nixpkgs-unstable": "nixpkgs-unstable",
         "nur": "nur",
         "sops-nix": "sops-nix",
-        "stylix": "stylix"
+        "stylix": "stylix",
+        "treefmt-nix": "treefmt-nix"
       }
     },
     "rust-overlay": {
@@ -721,6 +738,24 @@
         "repo": "default",
         "type": "github"
       }
+    },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": "nixpkgs_4"
+      },
+      "locked": {
+        "lastModified": 1729613947,
+        "narHash": "sha256-XGOvuIPW1XRfPgHtGYXd5MAmJzZtOuwlfKDgxX5KT3s=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "aac86347fb5063960eccb19493e0cadcdb4205ca",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
     }
   },
   "root": "root",