fix(income): погашения облигаций попадают в календарь выплат

У облигаций из ленты операций не было ни даты погашения, ни номинала, а погашение строилось именно от них. moex_payouts дописывает оба поля из паспорта бумаги (только пустые). Аналитика берёт дату погашения из графика номинала, если поля нет, считает сумму по номиналу накануне, а последний шаг амортизации не учитывает дважды.

backend/tests/analytics/test_income.py

@@ -117,6 +117,41 @@ def test_bond_entries_cover_coupon_amortisation_and_redemption():
     assert all(e.basis is IncomeBasis.schedule for e in entries)
 
 
+def test_a_bullet_bond_is_redeemed_on_the_day_its_schedule_reaches_zero():
+    """The OFZ 26226 case: no `maturity_date` on the instrument, one schedule row — zero."""
+    facts = BondFacts(
+        nominal=D(1000),
+        nominal_schedule=((date(2026, 10, 7), D(0)),),
+        maturity_date=None,
+        currency="RUB",
+    )
+    entries = bond_entries(1, facts, [], D(5), start=date(2026, 9, 20), end=date(2027, 9, 20))
+    assert [(e.kind, e.expected_date, e.per_unit, e.amount) for e in entries] == [
+        ("repayment", date(2026, 10, 7), D(1000), D(5000))
+    ]
+
+
+def test_the_last_amortisation_is_the_redemption_and_is_not_counted_twice():
+    facts = BondFacts(
+        nominal=D(1000),
+        nominal_schedule=(
+            (date(2026, 10, 1), D(500)),
+            (date(2027, 1, 1), D(200)),
+            (date(2027, 4, 1), D(0)),
+        ),
+        maturity_date=None,
+        currency="RUB",
+    )
+    entries = bond_entries(1, facts, [], D(10), start=date(2026, 9, 20), end=date(2027, 9, 20))
+    by_kind = [(e.kind, e.expected_date, e.amount) for e in entries]
+    # the first row of a plan has no earlier nominal to step down from, so it is not a step;
+    # the step to 200 is one, and the final 200 is repaid once — as the redemption
+    assert by_kind == [
+        ("amortization", date(2027, 1, 1), D(3000)),
+        ("repayment", date(2027, 4, 1), D(2000)),
+    ]
+
+
 def test_an_announced_payout_displaces_the_projection_of_the_same_payment():
     announced = [
         Entry(

backend/tests/sources/test_moex_payouts.py

@@ -286,6 +286,20 @@ def mock_iss(mock_http) -> None:
             ),
         )
     )
+    mock_http.get(url__startswith=f"{ISS}/securities/RU000A.json").mock(
+        return_value=httpx.Response(
+            200,
+            json=block(
+                "description",
+                ["name", "title", "value"],
+                [
+                    ["MATDATE", "Дата погашения", "2028-05-05"],
+                    ["FACEVALUE", "Номинальная стоимость", "750"],
+                    ["FACEUNIT", "Валюта номинала", "SUR"],
+                ],
+            ),
+        )
+    )
     mock_http.get(url__startswith=f"{ISS}/securities/SBER/dividends").mock(
         return_value=httpx.Response(
             200,
@@ -298,6 +312,37 @@ def mock_iss(mock_http) -> None:
     )
 
 
+async def test_a_bond_run_fills_the_maturity_and_nominal_the_instrument_lacks(
+    app, mock_http, run_sync
+):
+    """The redemption on the income calendar is built from these two fields."""
+    instrument_id = await seed(AssetClass.bond, "RU000A")
+    mock_iss(mock_http)
+
+    await run_sync(MoexPayoutsSource(), settings=Settings())
+
+    (instrument,) = await rows_of(Instrument, id=instrument_id)
+    assert instrument.maturity_date == date(2028, 5, 5)
+    assert instrument.nominal == D(750)
+    assert instrument.nominal_currency == "RUB"
+
+
+async def test_a_value_already_on_the_instrument_is_not_overwritten(app, mock_http, run_sync):
+    instrument_id = await seed(AssetClass.bond, "RU000A")
+    async with get_sessionmaker()() as session:
+        instrument = await session.get(Instrument, instrument_id)
+        assert instrument is not None
+        instrument.nominal = D(1000)
+        await session.commit()
+    mock_iss(mock_http)
+
+    await run_sync(MoexPayoutsSource(), settings=Settings())
+
+    (instrument,) = await rows_of(Instrument, id=instrument_id)
+    assert instrument.nominal == D(1000)  # what was there stays, whatever MOEX says today
+    assert instrument.maturity_date == date(2028, 5, 5)  # only the missing field is filled
+
+
 async def test_a_bond_run_writes_coupons_and_the_nominal_schedule(app, mock_http, run_sync):
     instrument_id = await seed(AssetClass.bond, "RU000A")
     mock_iss(mock_http)