chore(ci): preflight migration validation before deploy

.gitea/workflows/deploy.yml

@@ -78,6 +78,9 @@ jobs:
       - name: Copy migrations
         run: mkdir -p ./publish/db && cp -r db/migrations ./publish/db/ || true
 
+      - name: Validate migration version uniqueness
+        run: bash scripts/validate_migrations.sh db/migrations
+
       - name: Generate build info
         run: |
           COMMIT_HASH=$(git rev-parse --short HEAD)
@@ -109,6 +112,9 @@ jobs:
       - name: Package artifact
         run: |
           cp deploy_gb.sh ./publish/deploy_gb.sh
+          mkdir -p ./publish/scripts
+          cp scripts/validate_migrations.sh ./publish/scripts/validate_migrations.sh
+          chmod +x ./publish/scripts/validate_migrations.sh
           tar -czf taxbaik_deploy.tgz -C ./publish .
           echo "✓ Package: $(du -sh taxbaik_deploy.tgz | cut -f1)"
 
@@ -175,7 +181,12 @@ jobs:
           test -s "\$DEPLOY_DIR/proxy/TaxBaik.Proxy.dll" \
             || { echo "FATAL: TaxBaik.Proxy.dll 없음" >&2; exit 1; }
 
-          echo "--- [3/4] Green-Blue 배포 실행 ---"
+          echo "--- [3/5] 마이그레이션 사전 검증 ---"
+          test -x "\$DEPLOY_DIR/scripts/validate_migrations.sh" \
+            || { echo "FATAL: validate_migrations.sh 없음" >&2; exit 1; }
+          "\$DEPLOY_DIR/scripts/validate_migrations.sh" "\$DEPLOY_DIR/db/migrations" "postgresql://taxbaik:taxbaik123@localhost:5432/taxbaikdb"
+
+          echo "--- [4/5] Green-Blue 배포 실행 ---"
           chmod +x "\$DEPLOY_DIR/deploy_gb.sh"
           "\$DEPLOY_DIR/deploy_gb.sh" "\$DEPLOY_DIR"