add(nix-index): add nix index database and integration

flake.lock

@@ -326,6 +326,26 @@
         "type": "github"
       }
     },
+    "nix-index-database": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs-u"
+        ]
+      },
+      "locked": {
+        "lastModified": 1760241904,
+        "narHash": "sha256-OD7QnaGEVNdukYEbJbUNWPsvnDrpbZOZxVIk6Pt9Jhw=",
+        "owner": "nix-community",
+        "repo": "nix-index-database",
+        "rev": "c9f5ea45f25652ec2f771f9426ccacb21cbbaeaa",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nix-index-database",
+        "type": "github"
+      }
+    },
     "nix-rice": {
       "inputs": {
         "flake-parts": "flake-parts_2",
@@ -527,6 +547,7 @@
         "git-hooks": "git-hooks",
         "home-manager": "home-manager",
         "home-manager-u": "home-manager-u",
+        "nix-index-database": "nix-index-database",
         "nix-rice": "nix-rice",
         "nixos-generators": "nixos-generators",
         "nixos-hardware": "nixos-hardware",