test: restore into the same body scene; V3 mock asserts current=False

The checkpoint loader requires matching body count and geometry, so the
round-trip test rebuilds the three-circle scene before loading instead of
an empty simulation (loader unchanged). run_case.main now calls
verify_source(..., current=False); the two dry-run/run mock assertions
follow.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/validation/taylor_green/test_projected_pairs.py

@@ -361,7 +361,7 @@ class ProjectedPairsTests(unittest.TestCase):
                  patch.object(run_case, "runtime_identity", side_effect=AssertionError("CUDA reached")), \
                  redirect_stdout(stdout):
                 self.assertEqual(run_case.main(), 0)
-            verify.assert_called_once_with(REPO, MOCK_REVISION)
+            verify.assert_called_once_with(REPO, MOCK_REVISION, current=False)
             self.assertTrue(json.loads(stdout.getvalue())["dry_run"])
             self.assertFalse(output.exists())
 
@@ -454,7 +454,7 @@ class ProjectedPairsTests(unittest.TestCase):
                     else:
                         self.assertEqual(run_case.main(), 0)
                 receipt = json.loads(output.read_text())
-                verify.assert_called_once_with(REPO, MOCK_REVISION)
+                verify.assert_called_once_with(REPO, MOCK_REVISION, current=False)
                 self.assertEqual(selectors, ["projected_linear" if early else "constant"] if depth == 2 else [])
                 self.assertEqual(receipt["source"], source())
                 self.assertEqual(receipt["runtime_identity"], RUNTIME)