fix(api): detect registry URL vs image reference for Image provider

The Image provider UID was always passed as images=[uid], causing
registry URLs like docker.io/andoniaf to be treated as a single
image. Reuse the same heuristic from test_connection to pass
registry URLs as registry= instead, enabling image enumeration.

api/src/backend/api/utils.py

@@ -228,12 +228,32 @@ def get_prowler_provider_kwargs(
         # Keystone API is unavailable on public clouds.
         pass
     elif provider.provider == Provider.ProviderChoices.IMAGE.value:
-        # Image provider uses uid as the image reference; registry credentials
-        # come from the secret (all optional).
-        prowler_provider_kwargs = {
-            "images": [provider.uid],
-            **{k: v for k, v in prowler_provider_kwargs.items() if v},
-        }
+        # Detect whether uid is a registry URL (e.g. "docker.io/andoniaf") or
+        # a concrete image reference (e.g. "docker.io/andoniaf/myimage:latest").
+        # Uses the same heuristic as ImageProvider.test_connection.
+        from prowler.providers.image.image_provider import ImageProvider
+
+        image_uid = provider.uid
+        registry_host = ImageProvider._extract_registry(image_uid)
+        if registry_host:
+            repo_and_tag = image_uid[len(registry_host) + 1 :]
+        else:
+            repo_and_tag = image_uid
+
+        is_registry_url = (
+            registry_host and "/" not in repo_and_tag and ":" not in repo_and_tag
+        )
+
+        if is_registry_url:
+            prowler_provider_kwargs = {
+                "registry": image_uid,
+                **{k: v for k, v in prowler_provider_kwargs.items() if v},
+            }
+        else:
+            prowler_provider_kwargs = {
+                "images": [image_uid],
+                **{k: v for k, v in prowler_provider_kwargs.items() if v},
+            }
 
     if mutelist_processor:
         mutelist_content = mutelist_processor.configuration.get("Mutelist", {})