test: current-checkout mode for the projected-pair TG runner and assessor

run_case --current-checkout records the clean checkout (HEAD, src
fingerprint, harness hashes, pinned build-capture helper) labelled
current_checkout instead of requiring the frozen a135252 tree; receipts
carry numerical_revision=None. assess --current-checkout applies the same
gates to such receipts. Frozen mode is unchanged and now rejects any
receipt with source_mode, so the two never cross-qualify. A missing a135252
object is reported as unavailable history instead of a source diff.
check_projected_pairs.py is untouched, so its pinned hash and existing
receipts keep their meaning.

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

tests/validation/taylor_green/assess_projected_pairs.py

@@ -73,7 +73,10 @@ def valid_builds(record, n, depth):
     return True
 
 
-def assess(records, expected_revision=None):
+def assess(records, expected_revision=None, current=False):
+    """current=True assesses current-checkout receipts (run_case --current-checkout) with
+    the same gates; it never accepts them as the frozen a135252 qualification, and the
+    frozen mode never accepts current-checkout receipts."""
     indexed, duplicates = {}, []
     for record in records:
         key = tuple(record.get(k) for k in ("re_L", "n", "depth", "explosion"))
@@ -87,11 +90,19 @@ def assess(records, expected_revision=None):
     sources = [r.get("source", {}) for r in records]
     checks["same_source_and_harness"] = bool(sources) and len({
         json.dumps(s, sort_keys=True) for s in sources}) == 1
-    checks["clean_a135252_numerical_source"] = bool(sources) and all(
-        s.get("dirty") is False and s.get("source_tree_sha256") == SOURCE_SHA256
-        and bool(s.get("revision")) and bool(s.get("harness_sha256"))
-        and s.get("build_capture_sha256") == BUILD_CAPTURE_SHA256
-        and (expected_revision is None or s.get("revision") == expected_revision) for s in sources)
+    if current:
+        checks["clean_current_checkout_source"] = bool(sources) and expected_revision is not None and all(
+            s.get("dirty") is False and s.get("source_mode") == "current_checkout"
+            and bool(s.get("source_tree_sha256")) and bool(s.get("harness_sha256"))
+            and s.get("build_capture_sha256") == BUILD_CAPTURE_SHA256
+            and s.get("revision") == expected_revision for s in sources)
+    else:
+        checks["clean_a135252_numerical_source"] = bool(sources) and all(
+            s.get("dirty") is False and s.get("source_tree_sha256") == SOURCE_SHA256
+            and "source_mode" not in s
+            and bool(s.get("revision")) and bool(s.get("harness_sha256"))
+            and s.get("build_capture_sha256") == BUILD_CAPTURE_SHA256
+            and (expected_revision is None or s.get("revision") == expected_revision) for s in sources)
     runtimes = [r.get("runtime_identity") for r in records]
     checks["same_recorded_runtime"] = bool(runtimes) and all(
         isinstance(v, dict) and all(v.get(k) for k in
@@ -125,8 +136,14 @@ def assess(records, expected_revision=None):
             and r.get("mach") == U * math.sqrt(3)
         )
         checks[label + " actual_builds"] = valid_builds(r, n, depth)
-        checks[label + " reference"] = (r.get("numerical_revision") == NUMERICAL_REVISION
-                                         and r.get("reference_harness") == REFERENCE_HARNESS)
+        if current:
+            checks[label + " reference"] = (r.get("numerical_revision") is None
+                                             and r.get("source_mode") == "current_checkout"
+                                             and r.get("reference_harness") == REFERENCE_HARNESS)
+        else:
+            checks[label + " reference"] = (r.get("numerical_revision") == NUMERICAL_REVISION
+                                             and "source_mode" not in r
+                                             and r.get("reference_harness") == REFERENCE_HARNESS)
         checks[label + " numerics"] = r.get("numerics") == NUMERICS and r.get("initialization") == INITIALIZATION
         runtime = r.get("runtime_source", {})
         package = Path(runtime.get("checkout", "")) / "src/CelerisLab"
@@ -185,7 +202,10 @@ def assess(records, expected_revision=None):
                                      valid_case_and_controls=valid, baseline_passed=baseline_passed)
     return dict(passed=all(checks.values()), missing=missing, duplicates=duplicates, checks=checks,
                 comparisons=comparisons, scheme_results=scheme_results, early_pressure=early,
-                numerical_revision=NUMERICAL_REVISION, source_tree_sha256=SOURCE_SHA256,
+                source_mode="current_checkout" if current else "frozen",
+                numerical_revision=None if current else NUMERICAL_REVISION,
+                source_tree_sha256=(sources[0].get("source_tree_sha256") if current and sources
+                                    else None if current else SOURCE_SHA256),
                 reference_harness=REFERENCE_HARNESS, expected_revision=expected_revision,
                 floors=FLOORS, baseline_factor=BASELINE_FACTOR,
                 main_statistic="maximum of four post-initial samples at t*=.12,.24,.36,.48",
@@ -199,10 +219,13 @@ if __name__ == "__main__":
     p.add_argument("files", type=Path, nargs="+")
     p.add_argument("--output", type=Path, required=True)
     p.add_argument("--expected-revision", required=True)
+    p.add_argument("--current-checkout", action="store_true",
+                   help="assess current-checkout receipts; never the frozen qualification")
     args = p.parse_args()
     if args.output.exists():
         p.error("Output already exists; choose a new path to retain prior evidence")
-    result = assess([json.loads(path.read_text()) for path in args.files], args.expected_revision)
+    result = assess([json.loads(path.read_text()) for path in args.files], args.expected_revision,
+                    current=args.current_checkout)
     args.output.write_text(json.dumps(result, indent=2, allow_nan=False) + "\n")
     print(json.dumps(result, indent=2, allow_nan=False))
     raise SystemExit(0 if result["passed"] else 1)