feat(v0.3): Power-сервис на FSM — dev-mock кормит события, grace+durable-barrier

P7.2: service.rs оборачивает PowerFsm — D-Bus state/signals из FSM; apply_event
исполняет действия (эмит сигналов, фоновый grace-таймер, durable-barrier sync).
dev-mock SetAcc/SetIgnition/TriggerShutdown/AbortShutdown кормят входы FSM.
FSM: AccOff → AccChanged(false)+ShutdownImminent (сохранён walking-skeleton-регресс).
Integration: ShutdownImminent + abort. zbus → tokio-executor (default-features=false,
features=["tokio"]) — иначе tokio::spawn в хендлере паникует (async-io). test-integration
--test-threads=1 (тесты владеют одним именем на шине).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: Alexander <akotenev2003@gmail.com>

crates/core/shturman-power/src/fsm.rs

@@ -102,7 +102,16 @@ impl PowerFsm {
                 self.state = Accessory;
                 vec![]
             }
-            (Accessory | Running, E::AccOff) => self.begin_shutdown(ShutdownReason::AccOff),
+            // ACC-off: линия ACC сменилась (AccChanged) + старт shutdown.
+            (Accessory | Running, E::AccOff) => {
+                self.state = ShuttingDown { phase: Abortable, reason: ShutdownReason::AccOff };
+                vec![
+                    Action::AccChanged(false),
+                    Action::ShutdownImminent(ShutdownReason::AccOff),
+                    Action::StartGrace,
+                ]
+            }
+            // under-voltage/thermal: ACC не менялся → без AccChanged.
             (Accessory | Running, E::UnderVoltage) => self.begin_shutdown(ShutdownReason::UnderVoltage),
             (Accessory | Running, E::ThermalTrip) => self.begin_shutdown(ShutdownReason::Thermal),
             (ShuttingDown { phase: Abortable, .. }, E::AccOn) => {
@@ -149,7 +158,11 @@ mod tests {
         let mut f = PowerFsm::new(); // Running
         assert_eq!(
             f.step(Event::AccOff),
-            vec![Action::ShutdownImminent(ShutdownReason::AccOff), Action::StartGrace]
+            vec![
+                Action::AccChanged(false),
+                Action::ShutdownImminent(ShutdownReason::AccOff),
+                Action::StartGrace
+            ]
         );
         assert_eq!(f.power_state(), PowerState::ShuttingDown);
         assert_eq!(f.source(), PowerSource::HoldupCap);