Add some improvements

[artemkorsakov]

When we run sbt new creativescala/krop-fullstack.g8 command and set a package name with dots, for example, pdp.krop, we can recieve the error after ~backend/reStart serve runing:

backend 12:51:17.626 [io-compute-12] ERROR krop-asset-route(resources/pdp.krop/assets) -- Cannot create an asset route for resources/pdp.krop/assets as this path is not a directory.
backend[ERROR] java.lang.IllegalArgumentException: Cannot create an asset route for resources/pdp.krop/assets as this path is not a directory.

For example:

??? % sbt new creativescala/krop-fullstack.g8

Quick start for Krop projects with both a front and backend. 

name [Name Of The Project]: tempkrop
organization [org.theorganization]: ru.scalabook
package [tempkrop]: pdp.krop

After creating:

After running server:

sbt:tempkrop> ~backend/reStart serve
[info] compiling 1 Scala source to /.../tempkrop/shared/.jvm/target/scala-3.6.4/classes ...
[info] compiling 5 Scala sources to /.../tempkrop/backend/target/scala-3.6.4/classes ...
[info] Application backend not yet started
[info] Starting application backend in the background ...
backend Starting pdp.krop.Main.main(serve)
[success] Total time: 2 s, completed 26 июл. 2026 г., 12:51:16
[info] 1. Monitoring source files for root/backend/reStart serve...
[info]    Press <enter> to interrupt or '?' for more options.
backend 12:51:17.626 [io-compute-12] ERROR krop-asset-route(resources/pdp.krop/assets) -- Cannot create an asset route for resources/pdp.krop/assets as this path is not a directory.
backend[ERROR] java.lang.IllegalArgumentException: Cannot create an asset route for resources/pdp.krop/assets as this path is not a directory.

Maybe it's better to use "resources/assets/" folder for assets?