Fix folder marker size in ListObjects and improve Makefile

- Directories now report size 0 instead of filesystem block size (4096)
- Makefile clears test cache and greps for FAIL to catch errors

Author: pierre-b

Makefile

@@ -21,7 +21,8 @@ test-integration-up:
 	docker compose -f compose.test.yaml up -d --build
 	@echo "Waiting for container to be ready..."
 	@sleep 2
-	go test ./integration/... -v
+	go clean -testcache && go test ./integration/... -v 2>&1 | tee /tmp/integration-test.log; \
+	if grep -q "FAIL" /tmp/integration-test.log; then exit 1; fi
 
 # Stop test container
 test-integration-down:

internal/storage/storage.go

@@ -309,9 +309,15 @@ func (s *Storage) ListObjects(prefix string) ([]Object, error) {
 			return nil
 		}
 
+		// Directories report size 0 (S3 folder marker convention)
+		size := info.Size()
+		if info.IsDir() {
+			size = 0
+		}
+
 		objects = append(objects, Object{
 			Key:          key,
-			Size:         info.Size(),
+			Size:         size,
 			LastModified: info.ModTime(),
 			ContentType:  guessContentType(key),
 			ETag:         generateETag(info),