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/src/fintracker/metrics/refresh.py

@@ -1,8 +1,8 @@
 """Rebuild every metric_* table after data changed (plan §3).
 
-Order (each step is a function taking an AsyncSession and committing its own tables):
-    fx -> classify -> net worth -> cash flow -> spending -> runway -> data quality
-Phase 2 inserts prices/lots/valuation/holdings/returns between fx and net worth.
+Each step is a function taking an AsyncSession and committing its own tables. The steps and
+their order live in `analytics.register_steps`, with the reason for each dependency — this
+module only runs whatever is registered, in registration order.
 
 `refresh_all` is what the worker calls after a sync that reported `changed=True`, what the
 CLI `fintracker metrics refresh` runs, and what `POST /metrics/refresh` queues.
@@ -16,6 +16,7 @@ connection serialises them: a refresh that arrives during a sync WAITS and then
 from __future__ import annotations
 
 import logging
+import time
 import traceback
 from collections.abc import Awaitable, Callable
 from datetime import UTC, datetime
@@ -52,15 +53,22 @@ async def refresh_all(session: AsyncSession, trigger: str) -> MetricRefreshLog:
         entry = MetricRefreshLog(trigger=trigger)
         session.add(entry)
         await session.commit()
+        timings: dict[str, float] = {}
+        current: str | None = None
         try:
             for name, step in STEPS:
+                current = name
                 log.info("metrics: %s", name)
+                started = time.monotonic()
                 await step(session)
                 await session.commit()
+                timings[name] = round(time.monotonic() - started, 3)
         except Exception as exc:
             await session.rollback()
             entry.error = f"{type(exc).__name__}: {exc}\n{traceback.format_exc()[-4000:]}"
-            log.exception("metrics refresh failed at step")
+            entry.failed_step = current
+            log.exception("metrics refresh failed at step %s", current)
+        entry.step_timings = timings
         entry.finished_at = datetime.now(UTC)
         await session.commit()
         return entry