Validate C2PA credentials before attribution

tests/test_api.py

@@ -511,6 +511,15 @@ class TestSourceEvidenceHolder:
         assert holder.visible_provenance() == api.visible_provenance(DOUBAO)
         assert holder.has_invisible_target() == identify.has_invisible_target(DOUBAO)
 
+    def test_holder_preserves_invalid_c2pa_removal_hint(self, tampered_chatgpt_png):
+        from remove_ai_watermarks import api, identify
+
+        holder = api._SourceEvidence(tampered_chatgpt_png)
+
+        assert identify.identify(tampered_chatgpt_png, check_visible=False).ai_from_metadata is False
+        assert holder.has_invisible_target() is True
+        assert holder.has_invisible_target() == identify.has_invisible_target(tampered_chatgpt_png)
+
     def test_extraction_failure_fails_safe_in_both_directions(self, monkeypatch, tmp_path):
         """No provenance means no relaxation; an unknown invisible target means SCRUB.
         Leaving a watermark on a paid removal is worse than over-regenerating."""