Restore explicit-files discovery test

The test checks that explicit files skip a second discovery walk. It
failed only because its stub full scan had no html_report_url, which
create_full_scan_with_report_url now reads.

Author: lelia

tests/unit/test_manifest_discovery.py

@@ -282,6 +282,31 @@ def test_results_are_sorted_and_deduplicated_across_overlapping_patterns(tmp_pat
     assert len(found) == 2
 
 
+def test_explicit_discovery_results_prevent_a_second_walk(tmp_path):
+    manifest = tmp_path / "package.json"
+    manifest.write_text("{}", encoding="utf-8")
+    core = _make_core()
+    core.config.org_slug = "example"
+    core.cli_config = None
+    core.find_files = MagicMock(side_effect=AssertionError("unexpected second walk"))
+    core.create_full_scan = MagicMock(return_value=SimpleNamespace(id="scan-123", html_report_url=None))
+    params = MagicMock()
+
+    diff = core.create_full_scan_with_report_url(
+        [str(tmp_path)],
+        params,
+        explicit_files=[manifest.as_posix()],
+    )
+
+    core.find_files.assert_not_called()
+    core.create_full_scan.assert_called_once_with(
+        [manifest.as_posix()],
+        params,
+        base_paths=None,
+    )
+    assert diff.id == "scan-123"
+
+
 def test_core_initialization_logs_organization_timing(caplog):
     sdk = MagicMock()
     sdk.org.get.return_value = {