Fix manual.alarm_control_panel RestoreEntity bugs (#82990)

* manual: add previous state for TRIGGERED as well

This will be useful to properly restore timers on restart.

* manual: correctly restore timers on startup

homeassistant/components/manual/alarm_control_panel.py

@@ -358,7 +358,10 @@ def _async_update_state(self, state: str) -> None:
         self._state = state
         self._state_ts = dt_util.utcnow()
         self.async_schedule_update_ha_state()
+        self._async_set_state_update_events()
 
+    def _async_set_state_update_events(self) -> None:
+        state = self._state
         if state == STATE_ALARM_TRIGGERED:
             pending_time = self._pending_time(state)
             async_track_point_in_time(
@@ -403,6 +406,10 @@ def extra_state_attributes(self) -> dict[str, Any]:
                 ATTR_PREVIOUS_STATE: self._previous_state,
                 ATTR_NEXT_STATE: self._state,
             }
+        if self.state == STATE_ALARM_TRIGGERED:
+            return {
+                ATTR_PREVIOUS_STATE: self._previous_state,
+            }
         return {}
 
     @callback
@@ -414,14 +421,14 @@ async def async_added_to_hass(self) -> None:
         """Run when entity about to be added to hass."""
         await super().async_added_to_hass()
         if state := await self.async_get_last_state():
-            if (
-                state.state in (STATE_ALARM_PENDING, STATE_ALARM_ARMING)
-                and hasattr(state, "attributes")
-                and state.attributes[ATTR_PREVIOUS_STATE]
-            ):
-                # If in arming or pending state, we return to the ATTR_PREVIOUS_STATE
-                self._state = state.attributes[ATTR_PREVIOUS_STATE]
-                self._state_ts = dt_util.utcnow()
+            self._state_ts = state.last_updated
+            if hasattr(state, "attributes") and ATTR_NEXT_STATE in state.attributes:
+                # If in arming or pending state we record the transition,
+                # not the current state
+                self._state = state.attributes[ATTR_NEXT_STATE]
             else:
                 self._state = state.state
-                self._state_ts = state.last_updated
+
+            if hasattr(state, "attributes") and ATTR_PREVIOUS_STATE in state.attributes:
+                self._previous_state = state.attributes[ATTR_PREVIOUS_STATE]
+                self._async_set_state_update_events()