fix(ci): avoid postgres host port collision

.gitea/workflows/ci.yml

@@ -23,8 +23,6 @@ jobs:
           POSTGRES_USER: quantengine_ci
           POSTGRES_PASSWORD: quantengine_ci
           POSTGRES_DB: quantenginedb
-        ports:
-          - 5432:5432
         options: >-
           --health-cmd pg_isready
           --health-interval 5s
@@ -63,6 +61,8 @@ jobs:
     - name: Apply Database Migrations (CI Postgres service)
       env:
         PGPASSWORD: quantengine_ci
+        PGHOST: postgres
+        PGPORT: 5432
       run: |
         # QE-M2-01 등 스키마 존재만 확인하는 게이트는 실제 Postgres에 대해 재검증한다
         # (2026-07-12: WBS 게이트가 마이그레이션 SQL만으로 스키마를 주장하지 않도록,
@@ -70,9 +70,9 @@ jobs:
         which psql || (sudo apt-get update -qq && sudo apt-get install -y -qq postgresql-client)
         for f in $(ls src/dotnet/QuantEngine.Infrastructure/Migrations/V*.sql | sort -V); do
           echo "=== Applying $f ==="
-          psql -h 127.0.0.1 -p 5432 -U quantengine_ci -d quantenginedb -v ON_ERROR_STOP=1 -f "$f"
+          psql -U quantengine_ci -d quantenginedb -v ON_ERROR_STOP=1 -f "$f"
         done
-        echo "QE_WBS_PG_DSN=host=127.0.0.1 port=5432 dbname=quantenginedb user=quantengine_ci password=quantengine_ci options='-c search_path=quantengine'" >> "$GITHUB_ENV"
+        echo "QE_WBS_PG_DSN=host=postgres port=5432 dbname=quantenginedb user=quantengine_ci password=quantengine_ci options='-c search_path=quantengine'" >> "$GITHUB_ENV"
 
     - name: Setup .NET SDK
       uses: actions/setup-dotnet@v4