feat(SF2.0): Add The Squiggle for collapsed trip details

[joshlarson]

Scope

Asana Ticket: 📅🔎〰️ Draw the squiggle

Implementation

• Hand-rolled SVG's - I finally got to put my (very basic) understanding of Bézíer Curves to work!
• Fully replace the lined_list_item depending on whether the "more trips" section (this also resolves a kind of annoying visual bug where "Show fewer stops" wasn't aligned exactly the same as "Show more stops", so the text looked like it jumped around a little bit.
• 🤖 As part of an experiment, I've occasionally been using Copilot to do some tasks. The second commit in this PR was partially written with the help of Claude Code.

Screenshots

How to test

Go to any departures page and see how The Squiggle is there (when there are "more stops" to show), and disappears when "more stops" is expanded.

Notes

Looking at the page zoomed in and expanding "more stops" shows off the fact that the borders for expanded stops appear to be on top of the line diagram, as in the screenshot below. That's an existing issue, unrelated to the work in this PR, and is captured in a different ticket.

(This screenshot was taken in prod)

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Blocked by:

• feat: Set stroke color for mbta-route-*, same as fill color mbta_metro#35

Update: No longer blocked by work in mbta_metro.

[lvachon1]

Everything seems to look great except for the busses? It seems stroke-brand-bus is not doing anything?

[joshlarson]

@lvachon1 Great catch - thank you!

Fixed here, I think

[lvachon1]

Lookin good!