Change Render.com previews plan from starter to standard

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

Author: dadachi

render.yaml

@@ -8,7 +8,7 @@ services:
     name: nativeapptemplateapi
     plan: standard
     previews:
-      plan: starter
+      plan: standard
     env: ruby
     region: singapore # the region must be consistent across all services for the internal keys to be read
     buildCommand: "./bin/render-build.sh"