Fix macOS/iOS CI: chmod needs sudo, Nix store frameworks are root-owned

.github/workflows/macos.yml

@@ -22,10 +22,21 @@ jobs:
           extra_nix_config: experimental-features = nix-command flakes flake-self-attrs
 
       - name: Build app
-        run: nix develop --command bash -c "flutter pub get && dart scripts/generate.dart && flutter pub run build_runner build && flutter build macos --release"
+        run: |
+          nix develop --command bash -c '
+            set -e
+            flutter pub get
+            dart scripts/generate.dart
+            flutter pub run build_runner build
+
+            FLUTTER_ROOT="$(dirname "$(dirname "$(readlink -f "$(command -v flutter)")")")"
+            sudo find -L "$FLUTTER_ROOT" -type d -iname "*.framework" -exec chmod -R u+w {} +
+
+            flutter build macos --release
+          '
 
       - name: Upload installer artifact
         uses: actions/upload-artifact@v6
         with:
           name: App
-          path: build/macos/Build/Products/Release/Nexus.app
+          path: build/macos/Build/Products/Release/Nexus.app