fix: import result follows the commit; dropped route runs reach the store (#495)

Apply re-validated the preview token after both halves were durable, so a
TTL that lapsed during the write, or an eviction by a newer preview of the
same user, answered "preview expired" for a plan that was already replaced
and withheld both update events. The token is now simply spent after the
commit; validity is decided once, on entry under write_lock.

Route runs dropped by drop_unknown_routes never reached the store unless a
marker happened to be orphaned in the same pass; an idle robot kept them in
memory only and a restart brought them back. The drop now happens under
_refresh_lock, leaves with the orphan transaction or with an immediate
write of its own, and rolls back like #335 when the store refuses.

Tests: HA harness for both apply races and a live config/set route drop,
recorder stubs for the four durability cases; five mutants caught by the
standard runner.

Issue: #495
User-Visible: yes

docs/CHANGELOG.md

@@ -2,6 +2,14 @@
 
 ## Unreleased
 
+- Applying a backup import no longer reports "preview expired" after the plan
+  was already replaced: once both halves of the import are written, the result
+  and the update events follow the commit even if the preview timed out or was
+  displaced by a newer preview while the write was in flight. Deleting or
+  re-targeting a robot map route now removes its recorded runs from disk as
+  well as from memory, so a Home Assistant restart cannot bring them back
+  ([#495](https://github.com/Matysh/houseplan-card/issues/495)).
+
 ## v1.73.0-beta.7 — 2026-09-09
 
 - Summary-panel settings stay responsive with large Home Assistant installs:

docs/CHANGELOG.ru.md

@@ -8,6 +8,14 @@
 
 ## Не выпущено
 
+- Применение импорта из резервной копии больше не отвечает «preview expired»
+  после того, как план уже заменён: когда обе половины импорта записаны, ответ
+  и события обновления следуют за записью, даже если срок предпросмотра истёк
+  или его вытеснил более новый предпросмотр во время записи. Удаление или
+  перенацеливание маршрута карты робота теперь убирает записанные проезды и с
+  диска, а не только из памяти — перезапуск Home Assistant их не вернёт
+  ([#495](https://github.com/Matysh/houseplan-card/issues/495)).
+
 ## v1.73.0-beta.7 — 2026-09-09
 
 - Настройки сводной панели теперь остаются отзывчивыми даже при большом числе