fix: preserve unmanaged first-seen timestamps

Co-authored-by: genichin <4282227+genichin@users.noreply.github.com>

tests/adapters/portfolio/test_unmanaged_position_store.py

@@ -99,3 +99,30 @@ class TestCRUDRoundTrip:
         rows_b = pg_unmanaged_store.list_states(instance_key="inst-B", lifecycle_state="all")
         assert len(rows_a) == 1 and rows_a[0]["lifecycle_state"] == "resolved"
         assert len(rows_b) == 1 and rows_b[0]["quantity"] == 7
+
+    def test_reactivated_state_preserves_original_first_seen(self, pg_unmanaged_store):
+        t1 = datetime(2026, 9, 7, 0, 0, tzinfo=UTC)
+        t2 = t1 + timedelta(minutes=1)
+        t3 = t2 + timedelta(minutes=1)
+
+        pg_unmanaged_store.observe(
+            instance_key="inst-A",
+            symbol="008110",
+            quantity=3,
+            observed_at=t1,
+        )
+        pg_unmanaged_store.resolve_absent(
+            instance_key="inst-A",
+            observed_symbols=set(),
+            observed_at=t2,
+        )
+        reopened = pg_unmanaged_store.observe(
+            instance_key="inst-A",
+            symbol="008110",
+            quantity=5,
+            observed_at=t3,
+        )
+
+        assert reopened["transition"] == "detected"
+        assert reopened["state"]["first_seen_at"] == t1
+        assert reopened["state"]["last_seen_at"] == t3

tests/application/test_unmanaged_position_lifecycle.py

@@ -109,6 +109,22 @@ def test_in_memory_store_isolates_same_symbol_by_instance():
     assert state_b["quantity"] == 7
 
 
+def test_in_memory_store_preserves_first_seen_when_resolved_symbol_reappears():
+    store = InMemoryUnmanagedPositionStore()
+    t1 = datetime(2026, 9, 7, 0, 0, tzinfo=UTC)
+    t2 = t1 + timedelta(minutes=1)
+    t3 = t2 + timedelta(minutes=1)
+
+    store.observe(instance_key=INSTANCE, symbol="008110", quantity=3, observed_at=t1)
+    store.resolve_absent(instance_key=INSTANCE, observed_symbols=set(), observed_at=t2)
+    reopened = store.observe(instance_key=INSTANCE, symbol="008110", quantity=5, observed_at=t3)
+
+    assert reopened["transition"] == "detected"
+    assert reopened["state"]["first_seen_at"] == t1
+    assert reopened["state"]["last_seen_at"] == t3
+    assert reopened["state"]["quantity_changed_at"] == t3
+
+
 def test_reconcile_core_holdings_suppresses_repeated_unmanaged_alarm_spam():
     repo, svc = _wire()
     emitter, transport = _make_emitter()

trex_core/adapters/portfolio/unmanaged_position_store.py

@@ -58,11 +58,11 @@ class PostgreSQLUnmanagedPositionStore:
                         cur.execute(
                             "UPDATE unmanaged_position_state "
                             "SET quantity = %s, lifecycle_state = 'active', "
-                            "    first_seen_at = %s, last_seen_at = %s, quantity_changed_at = %s, "
-                            "    resolved_at = NULL, updated_at = %s "
+                            "    last_seen_at = %s, quantity_changed_at = %s, resolved_at = NULL, "
+                            "    updated_at = %s "
                             "WHERE instance_key = %s AND symbol = %s "
                             f"RETURNING {_STATE_COLUMNS}",
-                            (quantity, now, now, now, now, instance_key, symbol),
+                            (quantity, now, now, now, instance_key, symbol),
                         )
                     elif int(previous["quantity"]) != int(quantity):
                         transition = "quantity_changed"

trex_core/application/portfolio.py

@@ -629,7 +629,9 @@ class InMemoryUnmanagedPositionStore:
                     "symbol": symbol,
                     "quantity": quantity,
                     "lifecycle_state": "active",
-                    "first_seen_at": now,
+                    "first_seen_at": (
+                        existing.get("first_seen_at", now) if existing is not None else now
+                    ),
                     "last_seen_at": now,
                     "quantity_changed_at": now,
                     "resolved_at": None,