HOLD: Tint scholarship and CE credit cards to match their toggle state

[maebeale]

What is the goal of this PR and why is this important?

• On the event-registration edit screen, the Scholarship and CE credits cards previously colored only the toggle track when "Requested" was on, leaving the rest of the card neutral white.
• A requested scholarship or CE credit was easy to miss at a glance; the request status should read from across the card, not just the small switch.

How did you approach the change?

• Moved each card's Stimulus controller (scholarship-requested, ce-credit-requested) up onto the <section> so it can tint the whole box, not just the toggle.
• refresh() now mirrors the existing three-state logic onto the card itself: theme color when saved-on (fuchsia for scholarship, teal for CE), amber while the choice is pending (changed but unsaved), neutral white when off.
• Rendered the initial tint server-side so the correct color shows on load with no flash before Stimulus connects.
• An already-awarded scholarship has no toggle, so the controller guards on hasCheckboxTarget and leaves the static themed tint in place.

Anything else to add?

• Purely presentational — no model, controller, or behavior changes.
• border-teal-200 is the one new Tailwind utility; the rest were already in use. It's referenced from the ERB, so production/CI asset builds compile it.
• On HOLD pending the registration-edit redesign settling / design sign-off — opened as a draft so it's visible but not yet up for review.

[maebeale]

🤖 From Claude: Controller moved from the <label>/inner div up to the <section> so it can tint the whole card. This hasCheckboxTarget guard matters because an already-awarded scholarship renders no toggle — the controller still mounts, so without the guard refresh() would throw and clobber the server-rendered tint.