Keep original case provenance while revalidating a fresh caller session

Assistant: codex
Assistant-Model: gpt-6.1-sol
Assistant-Session: 01a14bfc-9643-7872-aa12-98326dcf25e7

src/warden/case_run.py

@@ -663,7 +663,20 @@ class Executor:
         materialization_evidence: str,
         descriptor_evidence: str,
         session_evidence: str,
+        original_session_reference: str | None = None,
     ) -> tuple[Descriptor, Invocation, StepState]:
+        # Current authentication is distinct from an immutable original receipt
+        # reference. The latter can only resume an exact existing journal intent;
+        # it is never passed to the current-session verifier as authority.
+        receipt_session = session_evidence
+        if original_session_reference is not None:
+            if (
+                type(original_session_reference) is not str
+                or not IDENTIFIER.fullmatch(original_session_reference)
+                or original_session_reference == session_evidence
+            ):
+                raise Refused("distinct original session reference required")
+            receipt_session = original_session_reference
         for source in (case_source, type_source, descriptor_source, catalog_source):
             bounded_source(source)
         descriptor = Descriptor.decode(descriptor_source)
@@ -781,7 +794,7 @@ class Executor:
                 acceptance_evidence,
                 materialization_evidence,
                 descriptor_evidence,
-                session_evidence,
+                receipt_session,
             ],
             separators=(",", ":"),
         ).encode()
@@ -803,6 +816,13 @@ class Executor:
             descriptor.allowed_created,
             descriptor.retry_safe,
         )
+        if original_session_reference is not None:
+            with self.journal.locked():
+                binding = f"{invocation.step}:{invocation.target}"
+                existing = self.journal.load(binding, initial)
+                if not existing.last:
+                    raise Refused("original dispatch journal required; no backfill")
+                self.journal.original_intent(binding, invocation, adapter.source)
         # Keep the mode and exact authenticated catalog bytes with this admission;
         # dispatch must not substitute a later ambient catalog or lose its mode.
         self._admitted[invocation] = (