chore(meta): bump supported version to 1.18 and add Roads to Power dependency

The mod was targeting CK3 1.12 which is several versions behind the
current 1.18 (Crane). Added Roads to Power DLC as a dependency in
both descriptor files.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lords_of_ash/descriptor.mod

@@ -3,4 +3,7 @@ tags={
 	"Total Conversion"
 }
 name="Mistborn: The Lords of Ash"
-supported_version="1.12.*"
+dependencies={
+	"Roads to Power"
+}
+supported_version="1.18.*"