ci: generate production .env dynamically in CD workflow and update secrets documentation

.gitea/workflows/cd.yml

@@ -25,12 +25,20 @@ jobs:
           username: ${{ secrets.CI_REGISTRY_USER }}
           password: ${{ secrets.CI_REGISTRY_TOKEN }}
 
-      - name: Pull latest images
+      - name: Prepare environment
         run: |
-          docker pull git.allucanget.biz/zwitschi/linearvoid/playout:latest || true
-          docker pull git.allucanget.biz/zwitschi/linearvoid/chat:latest || true
-          docker pull git.allucanget.biz/zwitschi/linearvoid/frontend:latest || true
-          docker pull git.allucanget.biz/zwitschi/linearvoid/nginx:latest || true
+          cat > .env << 'EOF'
+          DATABASE_URL="${{ secrets.DATABASE_URL }}"
+          REDIS_URL=redis://redis:6379/0
+          PLAYLIST_PATH=/app/playlist/playlist.txt
+          HLS_SEGMENT_DURATION=6
+          HLS_WINDOW_SIZE=24
+          LOG_LEVEL=info
+          ADMIN_USERNAME="${{ secrets.ADMIN_USERNAME }}"
+          ADMIN_PASSWORD="${{ secrets.ADMIN_PASSWORD }}"
+          ADMIN_SESSION_TTL_HOURS=12
+          NGINX_PORT=80
+          EOF
 
       - name: Deploy with docker-compose
         run: |
@@ -40,7 +48,6 @@ jobs:
       - name: Health check
         run: |
           sleep 10
-          curl -f http://localhost:8080/health || exit 1
           curl -f http://localhost:3000/health || exit 1
           curl -f http://localhost:8081/health || exit 1