CI: Electron-Build beschleunigt (~5min → ~2min)

- Custom Image electron-builder:latest (Mono + Docker CLI vorinstalliert)
- pull_policy: if-not-present (lokales Image, kein Registry-Pull)
- GitLab CI Cache für node_modules
- npm/Electron Cache-Verzeichnisse in /cache/
- npm ci --prefer-offline nutzt Cache wenn vorhanden
- before_script entfällt komplett (kein apt-get, kein curl)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitlab-ci.yml

@@ -69,7 +69,9 @@ docker-build:
 
 electron-build:
   stage: deploy
-  image: electronuserland/builder:wine
+  image:
+    name: electron-builder:latest
+    pull_policy: if-not-present
   needs: [deploy]
   rules:
     - if: $CI_COMMIT_BRANCH == "main"
@@ -80,15 +82,21 @@ electron-build:
       allow_failure: true
   variables:
     CONTAINER_NAME: "gaming-hub"
-  before_script:
-    - apt-get update && apt-get install -y --no-install-recommends mono-devel && rm -rf /var/lib/apt/lists/*
-    - curl -fsSL https://download.docker.com/linux/static/stable/x86_64/docker-27.5.1.tgz | tar xzv --strip-components=1 -C /usr/local/bin docker/docker
+    ELECTRON_CACHE: "/cache/electron"
+    electron_config_cache: "/cache/electron"
+    npm_config_cache: "/cache/npm"
+  cache:
+    key: electron-deps-${CI_COMMIT_REF_SLUG}
+    paths:
+      - electron/node_modules/
+    policy: pull-push
   script:
     - |
       VERSION=$(cat VERSION 2>/dev/null || echo "0.0.0")
       echo "[Electron] Building v${VERSION} for Windows..."
-      echo "[Electron] Wine: $(wine --version 2>/dev/null || echo 'not found')"
-      echo "[Electron] Mono: $(mono --version 2>/dev/null | head -1 || echo 'not found')"
+
+      # Cache-Verzeichnisse sicherstellen
+      mkdir -p "$ELECTRON_CACHE" "$npm_config_cache"
 
       cd electron
       node -e "
@@ -96,7 +104,9 @@ electron-build:
         pkg.version = '${VERSION}';
         require('fs').writeFileSync('package.json', JSON.stringify(pkg, null, 2) + '\n');
       "
-      npm ci --no-audit --no-fund
+
+      # npm ci mit Cache — prefer-offline nutzt Cache wenn vorhanden
+      npm ci --no-audit --no-fund --prefer-offline
       npx electron-forge make --platform win32 --arch x64
 
       # --- Deploy directly (no artifact upload needed) ---