Slow `npm install` during onboarding — large dependency tree

[christopheranderson]

Context

Split from #24 (sub-issue 3 of 4).

Problem

npm install for a scaffolded Rayfin project takes a long time to complete, especially on WSL (filesystem overhead). This hurts the first-run onboarding experience.

Expected Behavior

Install time should be reasonable for a scaffolded starter project. Users should see progress feedback during installation.

Suggested Improvements

• Audit the dependency tree for unnecessary or heavy packages
• Consider reducing the install footprint for starter templates
• Add progress feedback or timing expectations in the scaffold output (e.g., "Installing dependencies, this may take a minute...")
• Evaluate if some dependencies can be made optional or lazy-installed