memory extraction: make speaker person resolution deterministic

Co-Authored-By: GPT-5 Codex (OpenAI)

Author: dcramer

src/ash/memory/processing.py

@@ -444,7 +444,7 @@ async def process_extracted_facts(
                 try:
                     pids = await store.find_person_ids_for_username(source_username)
                     if pids:
-                        stated_by_pid = next(iter(pids))
+                        stated_by_pid = sorted(pids)[0]
                 except Exception:
                     logger.debug(
                         "stated_by_resolve_failed",

tests/test_memory.py

@@ -1108,6 +1108,43 @@ async def test_non_owner_subjects_unaffected(self, graph_store: Store):
         subject_pids = get_subject_person_ids(graph_store.graph, stored_ids[0])
         assert bob.id in subject_pids
 
+    @pytest.mark.asyncio
+    async def test_speaker_lookup_is_deterministic_when_multiple_ids(
+        self, graph_store: Store, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        """Speaker ID fallback should choose deterministically across set order."""
+        from ash.memory.processing import process_extracted_facts
+        from ash.store.types import ExtractedFact
+
+        async def fake_find_person_ids_for_username(_username: str) -> set[str]:
+            return {"pid-z", "pid-a"}
+
+        monkeypatch.setattr(
+            graph_store,
+            "find_person_ids_for_username",
+            fake_find_person_ids_for_username,
+        )
+
+        stored_ids = await process_extracted_facts(
+            facts=[
+                ExtractedFact(
+                    content="I prefer tea",
+                    subjects=[],
+                    shared=False,
+                    confidence=0.9,
+                    speaker="dave",
+                )
+            ],
+            store=graph_store,
+            user_id="user-1",
+        )
+
+        assert len(stored_ids) == 1
+        memory = graph_store.graph.memories[stored_ids[0]]
+        assert memory.metadata is not None
+        assertion = memory.metadata["assertion"]
+        assert assertion["speaker_person_id"] == "pid-a"
+
 
 class TestDMSensitivityFloor:
     """Tests for DM sensitivity floor on ephemeral memory types."""