iced-template: use more efficient nixpkgs input

the type alias Element is quite useful for defining subfunctions for view
and it also helps to not pull unnecessary things into scope

flake.lock

@@ -20,18 +20,15 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1785747939,
-        "narHash": "sha256-D740uKsMbgsfK2oaDenJLLPIZfq7W0/g4KN/Fls8eKs=",
-        "owner": "nixos",
-        "repo": "nixpkgs",
-        "rev": "104240a772428cc2e20d8fd86c9ddbb886bbaff2",
-        "type": "github"
+        "lastModified": 1786862985,
+        "narHash": "sha256-kSR/jfpR4cE26YRZ8exQkoRbEA30vyWimajwZANYYaE=",
+        "rev": "e5bdc4a41d4c072fe1e3787eaa0320a384741d44",
+        "type": "tarball",
+        "url": "https://releases.nixos.org/nixos/unstable/nixos-26.11pre1055335.e5bdc4a41d4c/nixexprs.tar.zst?lastModified=1786862985&rev=e5bdc4a41d4c072fe1e3787eaa0320a384741d44"
       },
       "original": {
-        "owner": "nixos",
-        "ref": "nixpkgs-unstable",
-        "repo": "nixpkgs",
-        "type": "github"
+        "type": "tarball",
+        "url": "https://channels.nixos.org/nixos-unstable/nixexprs.tar.zst"
       }
     },
     "root": {

flake.nix

@@ -1,6 +1,6 @@
 {
   inputs = {
-    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+    nixpkgs.url = "https://channels.nixos.org/nixos-unstable/nixexprs.tar.zst";
 
     flake-utils.url = "github:numtide/flake-utils";
   };
@@ -49,7 +49,6 @@
             desktopItem = pkgs.makeDesktopItem {
               inherit name;
               desktopName = name;
-              icon = name;
               exec = name;
             };
           in

src/app/mod.rs

@@ -1,4 +1,6 @@
-use iced::{Color, Element, Renderer, Task, Theme, application, theme, widget};
+use iced::{Color, Task, application, theme, widget};
+
+type Element<'a> = iced::Element<'a, Message, iced::Theme, iced::Renderer>;
 
 enum Message {}
 
@@ -11,12 +13,12 @@ impl State {
     fn update(&mut self, message: Message) -> Task<Message> {
         Task::none()
     }
-    fn view(&self) -> Element<'_, Message, Theme, Renderer> {
+    fn view(&self) -> Element<'_> {
         widget::text("hiiiiiii").into()
     }
 }
 
-pub fn run() -> Result<(), impl std::error::Error> {
+pub fn run() -> Result<(), iced::Error> {
     application(State::new, State::update, State::view)
         .theme(theme::Theme::custom(
             "high-contrast-dark",