feat(worker): ручной пересчёт метрик через очередь, диагностика шагов и heartbeat

POST /metrics/refresh ставит задачу в sync_job (source=METRICS_JOB) и отвечает 202, пересчёт делает worker; GET /metrics/status отдаёт refreshing и consistent. metric_refresh_log хранит failed_step и step_timings. Источники с needs="tinvest_token" не попадают в расписание без токена, tinvest/moex добавлены в default_schedule. Воркер трогает heartbeat-файл для healthcheck.

backend/tests/test_schedule.py

@@ -0,0 +1,49 @@
+"""The timetable only names sources that exist, and leaves off the ones that cannot run."""
+
+from __future__ import annotations
+
+from fintracker.config import Settings
+from fintracker.sources import registry
+from fintracker.worker.jobs import default_schedule, scheduled
+
+
+def test_every_scheduled_source_is_registered_once():
+    names = [s.source for s in default_schedule()]
+    assert len(names) == len(set(names))
+    assert set(names) <= set(registry.names())
+
+
+def test_every_live_source_is_on_the_timetable():
+    assert {s.source for s in default_schedule()} == set(registry.names())
+
+
+def test_sources_needing_a_token_are_left_off_without_one():
+    ready, skipped = scheduled(Settings.model_construct(tinvest_token=None))
+    assert {s.source for s in skipped} == {"tinvest", "tinvest_events"}
+    assert not {s.source for s in ready} & {"tinvest", "tinvest_events"}
+
+    ready, skipped = scheduled(Settings.model_construct(tinvest_token="t.x"))
+    assert skipped == []
+    assert {"tinvest", "moex", "tinvest_events", "moex_payouts"} <= {s.source for s in ready}
+
+
+def test_needs_names_a_real_setting():
+    for spec in default_schedule():
+        if spec.needs is not None:
+            assert spec.needs in Settings.model_fields
+
+
+def test_worker_timetable_has_the_heartbeat_and_the_queue_poller():
+    from fintracker.worker.scheduler import build_scheduler
+
+    ids = {j.id for j in build_scheduler().get_jobs()}
+    assert {"heartbeat", "poll-sync-jobs", "sync:zenmoney", "sync:moex", "sync:moex_payouts"} <= ids
+
+
+async def test_heartbeat_touches_its_file(tmp_path, monkeypatch):
+    from fintracker.worker import scheduler
+
+    beat = tmp_path / "beat"
+    monkeypatch.setattr(scheduler, "HEARTBEAT_FILE", beat)
+    await scheduler._heartbeat()
+    assert beat.exists()