Apply animation workflow, sidebar, and template updates

[han4wluc]

Summary

• remove the read-only Runtime page and redirect the legacy route to Variables
• create animations immediately from the add flow, refine animation editor mask defaults and controls, and add scene detail preview support
• refresh the projects screen and create-project helper text, plus update sidebar/category icons
• update the default template assets, backgrounds, transforms, and package versions for route-engine-js and route-graphics

Verification

• bun run build:tauri