Add supply auto-purchase and preserve save recovery state

scripts/defense/defense_service.gd

@@ -1542,6 +1542,8 @@ func _raid_from_snapshot(raw: Dictionary) -> Dictionary:
 	var state_index := RaidState.keys().find(String(_value(raw, &"state", &"")))
 	if raid_id.is_empty() or state_index < 0:
 		return {&"ok": false, &"error": "Raid snapshot ID or state is invalid."}
+	# Normal creation owns Array[Dictionary]; restores keep the same container type.
+	var parsed_waves: Array[Dictionary] = []
 	var raid := {
 		&"raid_id": raid_id,
 		&"source_id": StringName(_value(raw, &"source_id", &"")),
@@ -1564,7 +1566,7 @@ func _raid_from_snapshot(raw: Dictionary) -> Dictionary:
 		&"multiple_entry_penalty": int(_value(raw, &"multiple_entry_penalty", -1)),
 		&"entry_points": _sorted_unique_names(_value(raw, &"entry_points", [])),
 		&"objective_ids": _sorted_unique_names(_value(raw, &"objective_ids", [])),
-		&"waves": [],
+		&"waves": parsed_waves,
 		&"combatants": {},
 		&"assets": {},
 		&"queued_skills": {},
@@ -1588,7 +1590,7 @@ func _raid_from_snapshot(raw: Dictionary) -> Dictionary:
 		wave[&"objective_ids"] = _sorted_unique_names(_value(wave, &"objective_ids", []))
 		wave[&"state"] = StringName(_value(wave, &"state", &""))
 		wave[&"result_reason"] = StringName(_value(wave, &"result_reason", &""))
-		(raid[&"waves"] as Array).append(wave)
+		parsed_waves.append(wave)
 	for raw_combatant: Variant in _value(raw, &"combatants", []):
 		if not raw_combatant is Dictionary:
 			return {&"ok": false, &"error": "Malformed defense combatant snapshot."}