add dev flake

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -1,2 +1,6 @@
 /target
 upload/*
+/data
+.direnv
+.env
+result

flake.lock

@@ -0,0 +1,107 @@
+{
+  "nodes": {
+    "crane": {
+      "locked": {
+        "lastModified": 1780099841,
+        "narHash": "sha256-EVZd2RsbpreRUDSi9rBwPY+ZxoyMaiEBbZxxhljbaS4=",
+        "owner": "ipetkov",
+        "repo": "crane",
+        "rev": "0532eb17955225173906d671fb36306bdeb1e2dc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "ipetkov",
+        "repo": "crane",
+        "type": "github"
+      }
+    },
+    "flakelight": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1779722240,
+        "narHash": "sha256-cX1d9V5JHTytsSdH8RrgyU4fFdm4oooRuKBcJuiyI4U=",
+        "owner": "nix-community",
+        "repo": "flakelight",
+        "rev": "6908ac68dd682d1cb22fdb9391b890798f083a48",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "flakelight",
+        "type": "github"
+      }
+    },
+    "mill-scale": {
+      "inputs": {
+        "crane": "crane",
+        "flakelight": [
+          "flakelight"
+        ],
+        "rust-overlay": "rust-overlay"
+      },
+      "locked": {
+        "lastModified": 1780231986,
+        "narHash": "sha256-OyafczPtzE0Xa2zl3j/KvV2+ZVYGhYQHt0MOVWtDXlY=",
+        "ref": "refs/heads/main",
+        "rev": "f5cbda29b945df03256bf63c22fa4cd5fa429e67",
+        "revCount": 72,
+        "type": "git",
+        "url": "https://codeberg.org/icewind/mill-scale"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://codeberg.org/icewind/mill-scale"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1780051219,
+        "narHash": "sha256-WnxzG4x47uCgjz+uD+vOzbF+Qid+hKyYdJWbduA9w7g=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e8e446a361172fe838243958325845d0b845c5e5",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-26.05",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flakelight": "flakelight",
+        "mill-scale": "mill-scale",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "nixpkgs": [
+          "mill-scale",
+          "flakelight",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1780197589,
+        "narHash": "sha256-FVCr2Ij/jKf59a4LW481eeOF6rJRreOBrVgW/aUBTrw=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "21632e942d89bf1cce4e5a63d7e58a215a0cbfcc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,15 @@
+{
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-26.05";
+    flakelight = {
+      url = "github:nix-community/flakelight";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    mill-scale = {
+      url = "git+https://codeberg.org/icewind/mill-scale";
+      inputs.flakelight.follows = "flakelight";
+    };
+  };
+  outputs = {mill-scale, ...}:
+    mill-scale ./. {};
+}