nix: add standalone project flake

AGENTS.md

@@ -16,6 +16,7 @@ sockets.
 - `src/model.rs`: client data, application grouping, address normalization, and
   focus history.
 - `src/desktop.rs`: XDG desktop-file metadata and icon lookup.
+- `flake.nix`: standalone Nix package, app, checks, and development shell.
 - `../hyprland.conf`: source configuration integration. The live config may be
   deployed from another checkout; verify it before editing or reloading.
 
@@ -53,6 +54,7 @@ cargo fmt --check
 cargo test
 cargo clippy --workspace --all-targets -- -D warnings
 cargo build --release
+nix flake check
 ```
 
 Install a tested build with:
@@ -80,4 +82,3 @@ proportional runtime checks in a live Hyprland session.
 Preserve unrelated dirty changes in both configuration checkouts. Use
 `readlink -f ~/.config/hypr/hyprland.conf` before assuming the workspace copy is
 the active one.
-

README.md

@@ -40,6 +40,23 @@ other workspaces.
 
 ## Build and install
 
+### Nix
+
+The project flake owns the Rust and GTK build dependencies. Build or run the
+locked package directly:
+
+```sh
+nix build
+nix run . -- show
+```
+
+Use `nix develop` for a shell containing Cargo, Clippy, rustfmt, and the native
+GTK dependencies. Downstream flakes can install
+`packages.${system}.default` and make this flake's `nixpkgs` input follow
+their own.
+
+### Cargo
+
 Run this from the directory containing this README:
 
 ```sh
@@ -48,8 +65,9 @@ cargo clippy --workspace --all-targets -- -D warnings
 cargo install --path . --root ~/.local --force
 ```
 
-The binary is installed as `~/.local/bin/hypr-switcher`. The accompanying
-`../hyprland.conf` starts the daemon and defines the bindings:
+The binary is installed as `~/.local/bin/hypr-switcher`. A Nix profile usually
+exposes it as `~/.nix-profile/bin/hypr-switcher`. Configure the applicable
+absolute path, then start the daemon and define the bindings:
 
 ```ini
 $switcher = ~/.local/bin/hypr-switcher

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1786862985,
+        "narHash": "sha256-FBJRXmbGXiSUDvYEbfLYRkckayyZ6SK1UEqhCrIZ2Cs=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e5bdc4a41d4c072fe1e3787eaa0320a384741d44",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,84 @@
+{
+  description = "macOS-style application switching and hiding for Hyprland";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      supportedSystems = [
+        "x86_64-linux"
+        "aarch64-linux"
+      ];
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+      pkgsFor = system: import nixpkgs { inherit system; };
+    in
+    {
+      packages = forAllSystems (
+        system:
+        let
+          pkgs = pkgsFor system;
+        in
+        rec {
+          hypr-switcher = pkgs.rustPlatform.buildRustPackage {
+            pname = "hypr-switcher";
+            version = "0.1.0";
+            src = pkgs.lib.cleanSource ./.;
+
+            cargoLock.lockFile = ./Cargo.lock;
+
+            nativeBuildInputs = with pkgs; [
+              pkg-config
+              wrapGAppsHook4
+            ];
+
+            buildInputs = with pkgs; [
+              gtk4
+              gtk4-layer-shell
+            ];
+
+            meta = {
+              description = "macOS-style application switcher for Hyprland";
+              homepage = "https://code.buzzert.dev/buzzert/hypr-switcher";
+              mainProgram = "hypr-switcher";
+              platforms = pkgs.lib.platforms.linux;
+            };
+          };
+
+          default = hypr-switcher;
+        }
+      );
+
+      apps = forAllSystems (system: {
+        hypr-switcher = {
+          type = "app";
+          program = "${self.packages.${system}.hypr-switcher}/bin/hypr-switcher";
+        };
+        default = self.apps.${system}.hypr-switcher;
+      });
+
+      checks = forAllSystems (system: {
+        default = self.packages.${system}.hypr-switcher;
+      });
+
+      devShells = forAllSystems (
+        system:
+        let
+          pkgs = pkgsFor system;
+        in
+        {
+          default = pkgs.mkShell {
+            inputsFrom = [ self.packages.${system}.hypr-switcher ];
+            packages = with pkgs; [
+              cargo
+              clippy
+              rustc
+              rustfmt
+            ];
+          };
+        }
+      );
+
+      formatter = forAllSystems (system: (pkgsFor system).nixfmt);
+    };
+}