Update CI configuration for Flutter environment setup

ci.yml

@@ -4,16 +4,18 @@
 schemaVersion: v0.2
 prepare:
   steps:
-    - name: Prepare Flutter Environment
+    - name: Install Flutter toolchain
       command: nix-env -i -f ~/app/configuration.nix
+    - name: Trim Flutter targets
+      command: flutter config --no-analytics --no-enable-android --no-enable-ios --no-enable-linux-desktop --no-enable-macos-desktop --no-enable-windows-desktop --enable-web
     - name: Install Frontend Dependencies
       command: cd /home/user/app/frontend/ && flutter pub get
     - name: Build Flutter Web App
-      command: cd /home/user/app/frontend/ && flutter clean && flutter build web
-    - name: Check Dart Version
-      command: dart --version
+      command: cd /home/user/app/frontend/ && flutter build web --release
     - name: Test Backend Compilation
       command: cd /home/user/app/backend/ && dart analyze bin/server.dart
+    - name: Reclaim disk
+      command: nix-collect-garbage -d && nix-store --optimise && rm -rf /home/user/app/frontend/.dart_tool /home/user/.pub-cache/.tmp
 test:
   steps: []
 run:

configuration.nix

@@ -1,18 +1,4 @@
-{ pkgs ? import <nixpkgs> {
-    config = {
-    };
-  },
-}:
-
-
+{ pkgs ? import <nixpkgs> {}, }:
 with pkgs; [
-  flutter                  # Flutter SDK for building the frontend
-  pkg-config               # For package configuration
-  jdk17                    # Java Development Kit, needed for Android
-  gtk3                     # GTK3, used by Flutter on Linux and macOS
-  xorg.libX11              # Required for Flutter on Linux systems
-  glib                     # Library required by various components
-  dbus                     # Required for interprocess communication
-  pcre2                    # PCRE2 for regex support
-  go                       # Go programming language for backend development
+  flutter   # includes the Dart SDK used by the backend
 ]