fix: roll back rejected marker writes atomically

Issue: #442
User-Visible: yes

docs/CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## Unreleased
 
+- Rejected device-marker and robot-calibration saves now restore the last
+  server-confirmed plan without losing the open editor, automatic proposal or
+  manual-fit draft; success is shown only after Home Assistant accepts the
+  write, and Retry no longer requires recalibration
+  ([#442](https://github.com/Matysh/houseplan-card/issues/442)).
 - Removing a robot vacuum's last map route now keeps the route list explicitly
   empty instead of reviving legacy calibration; routes to deleted spaces are
   grouped clearly in the editor, and the live layer avoids rescanning every

docs/CHANGELOG.ru.md

@@ -8,6 +8,11 @@
 
 ## Не выпущено
 
+- Если Home Assistant отклоняет сохранение устройства или калибровки робота,
+  план теперь возвращается к последнему подтверждённому состоянию, но сохраняет
+  открытый редактор, автоматическое предложение или ручную подгонку для повтора;
+  сообщение об успехе появляется только после принятой записи
+  ([#442](https://github.com/Matysh/houseplan-card/issues/442)).
 - После удаления последнего маршрута карты робота список теперь остаётся явно
   пустым и не возвращает старую калибровку; маршруты в удалённые пространства
   собраны в понятную группу, а живой слой больше не перебирает повторно все

docs/CONFIG-COMPATIBILITY.md

@@ -556,6 +556,22 @@ full/space transfer preserve, remap or report/drop `derived_marker_state.ref`
 through the same reference seam as controls and value badges. Older clients
 ignore the field and may erase it if they reconstruct the marker.
 
+## Atomic marker writes (#442)
+
+The Device editor builds a separate complete config candidate and treats a
+successful `houseplan/config/set` response as the durable boundary. If semantic
+validation, transport or schema validation rejects that request, the card
+restores the preceding server-confirmed config and content fingerprint, rebuilds
+the visible marker set, and keeps the independent dialog draft available for
+Retry. A revision loaded after a conflict or newer local content always wins;
+an older rejection cannot overwrite either one.
+
+Layout placement, obsolete-layout cleanup and copied-file cleanup happen only
+after config acceptance. Their failure can report an error and keep the dialog
+open, but cannot roll back a marker already accepted by the server. This is a
+frontend transaction contract only: marker schema, validators, revision wire
+format and downgrade behaviour are unchanged.
+
 ## Persistent manual virtual-light state
 
 The exact `virtual` + `is_light:true` + `tap_action:toggle` combination has a

docs/VACUUM.md

@@ -126,6 +126,15 @@ At `> 40 cm` nothing is saved until the user explicitly chooses **Apply**.
 **Fit manually** opens the proposal in the fit overlay; **Cancel** leaves the
 saved configuration byte-for-byte unchanged.
 
+Calibration Save is complete only after Home Assistant accepts the config
+write. While it is pending, automatic-calibration controls, a high-residual
+proposal or the manual-fit overlay stay busy and cannot submit, close or move a
+second draft. On rejection the last accepted matrix is restored immediately:
+the Device editor remains open, a high-residual proposal keeps its exact matrix,
+and manual fit keeps its exact transform for Retry. A rejected first-use
+calibration also removes the unaccepted synthetic marker. Success closes the
+relevant proposal/overlay and appears only after server acceptance.
+
 Map ID uses one nullish chain and deliberately ignores volatile values such as
 `vacuum_json_id`: