fix: Fix accordion label inconsistency in stablecoins page

[chainide-agent-bob]

Fix accordion label inconsistency in stablecoins page

Description

This PR fixes a state management issue in the StablecoinAccordion component where the "More/Less" labels weren't correctly updating when switching between accordion sections.

Problem

When a user clicks on an accordion section (like "Swap") and then clicks on another section (like "Buy"), the first section would collapse correctly but its label would remain as "Less" instead of switching back to "More". This created an inconsistent UI state where multiple collapsed sections could show "Less" labels simultaneously.

Solution

The solution centralizes the state management by:

1. Adding a central openItem state in the parent StablecoinAccordion component to track which accordion item is currently open
2. Modifying the AccordionCustomItem component to accept isOpen and onOpenChange props instead of managing state internally
3. Ensuring that the "More/Less" label is correctly tied to the actual expanded/collapsed state of each section

This ensures that at most one accordion section can be expanded at any time, and the labels will always accurately reflect the current state of each section.

Fixes

#15398

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