P06-01: Fix review r01 findings for A06 reserve

Settle Mana raised above capacity between boundaries as recorded overflow
instead of rejecting saves or latching a fault, exclude destroyed facilities
from upkeep demand, and keep the depletion drill's outage sustained.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/mvp/test_runtime_mana_depletion.gd

@@ -1,4 +1,5 @@
 extends SceneTree
+const ManaOutage = preload("res://tests/helpers/mana_outage.gd")
 var checks := 0
 var failures := 0
 func _initialize() -> void:
@@ -31,11 +32,12 @@ func _run() -> void:
 		runtime.free(); clock.free(); state.free(); quit(failures); return
 	# Only reserve depletion is a diagnostic input; no numeric generation policy
 	# is asserted by this test. Everything else advances through Runtime ticks.
-	state.set_resource(&"mana", 0)
+	ManaOutage.hold(runtime, state)
 	# Pre-fix saves legitimately contain zero reserve with old powered flags.
 	var legacy: Dictionary = runtime.create_snapshot()
 	var legacy_data: Dictionary = legacy[&"systems"][&"runtime"]
 	legacy_data[&"runtime_schema_version"] = 9
+	legacy_data.erase(&"mana_reserve")
 	preload("res://tests/fixtures/pre_upkeep_runtime.gd").strip_empty_upkeep(legacy_data)
 	var source_copy := legacy.duplicate(true)
 	var old_reception_id := reception.instance_id
@@ -65,7 +67,7 @@ func _run() -> void:
 	var room_id := room.instance_id
 	var reception_id := reception.instance_id
 	runtime.facility_service.set_operational_status(room_id, {&"suspension_reason": &"DESTROYED"}, clock.absolute_minute)
-	state.set_resource(&"mana", 1)
+	ManaOutage.release(runtime, state, 1)
 	clock.advance_minutes(1)
 	room = runtime.facility_service.get_instance(room_id)
 	reception = runtime.facility_service.get_instance(reception_id)