fix(ci): allow empty QUANTENGINE_DB_PASSWORD, fix heredoc env file generation

.gitea/workflows/deploy-prod.yml

@@ -141,10 +141,10 @@ jobs:
         run: |
           echo "🔧 Preparing database environment..."
 
-          # 환경 변수 검증
-          if [ -z "${{ secrets.QUANTENGINE_DB_PASSWORD }}" ]; then
-            echo "❌ QUANTENGINE_DB_PASSWORD secret not configured"
-            exit 1
+          # QUANTENGINE_DB_PASSWORD: 미설정 시 빈 문자열로 처리 (pg_hba.conf trust 모드 대응)
+          DB_PASSWORD="${{ secrets.QUANTENGINE_DB_PASSWORD }}"
+          if [ -z "$DB_PASSWORD" ]; then
+            echo "⚠️  QUANTENGINE_DB_PASSWORD not set — using empty password (trust auth mode)"
           fi
 
           if [ -z "${{ env.QUANTENGINE_DB_NAME }}" ] || [ -z "${{ env.QUANTENGINE_DB_USER }}" ]; then
@@ -154,9 +154,10 @@ jobs:
 
           # 환경 파일 생성
           mkdir -p ./deploy
-          cat > ./deploy/quantengine.env <<EOF
-          ConnectionStrings__DefaultConnection=Host=127.0.0.1;Database=${{ env.QUANTENGINE_DB_NAME }};Username=${{ env.QUANTENGINE_DB_USER }};Password=${{ secrets.QUANTENGINE_DB_PASSWORD }};Search Path=quantengine;
-          EOF
+          printf 'ConnectionStrings__DefaultConnection=Host=127.0.0.1;Database=%s;Username=%s;Password=%s;Search Path=quantengine;\n' \
+            "${{ env.QUANTENGINE_DB_NAME }}" \
+            "${{ env.QUANTENGINE_DB_USER }}" \
+            "$DB_PASSWORD" > ./deploy/quantengine.env
           chmod 600 ./deploy/quantengine.env
 
           # 파일 검증