Add .gitignore, use manifest v2

.gitignore

@@ -0,0 +1 @@
+web-ext-artifacts/

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1755615617,
+        "narHash": "sha256-HMwfAJBdrr8wXAkbGhtcby1zGFvs+StOp19xNsbqdOg=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "20075955deac2583bb12f07151c2df830ef346b4",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

manifest.json

@@ -1,5 +1,5 @@
 {
-  "manifest_version": 3,
+  "manifest_version": 2,
   "name": "yt-share-cleaner",
   "version": "0.0.1",