ci: manual Windows desktop build job (allow_failure)

.gitlab-ci.yml

@@ -9,6 +9,7 @@ image: ghcr.io/cirruslabs/flutter:3.41.9
 stages:
   - analyze
   - test
+  - build
 
 variables:
   PUB_CACHE: "$CI_PROJECT_DIR/.pub-cache"
@@ -38,6 +39,33 @@ test:commons_core:
     - cd packages/commons_core
     - dart test
 
+# Windows desktop build. Needs a Windows runner: on gitlab.com the SaaS
+# `saas-windows-medium-amd64` shared runners (Windows Server 2022 with Visual
+# Studio 2022 Build Tools — the C++ workload Flutter requires). Manual +
+# allow_failure until the canonical remote actually has Windows runners.
+build:windows:
+  stage: build
+  tags:
+    - saas-windows-medium-amd64
+  rules:
+    - when: manual
+      allow_failure: true
+  # The global Linux image is ignored on Windows shell runners; override the
+  # global before_script (apt-get) — this job runs in PowerShell.
+  before_script:
+    - git clone --depth 1 -b stable https://github.com/flutter/flutter.git "$env:CI_PROJECT_DIR\.flutter"
+    - $env:PATH = "$env:CI_PROJECT_DIR\.flutter\bin;$env:PATH"
+    - flutter --version
+    - flutter pub get
+  script:
+    - cd apps\app_seeds
+    - dart run slang
+    - dart run build_runner build --delete-conflicting-outputs
+    - flutter build windows --release
+  artifacts:
+    paths:
+      - apps/app_seeds/build/windows/x64/runner/Release/
+
 test:app_seeds:
   stage: test
   script: