fix: settings modal scrolling and viewport clipping

[maxtara]

Problem

The settings modal had two issues:

1. Content was not scrollable when it exceeded the modal height
2. On small windows, the modal could get clipped at the top/bottom edges

Changes

Modal.tsx:

• Added max-h-[90vh] to limit modal to 90% of viewport height
• Added lex flex-col to make modal a flex container for proper child layout
• Added my-4 for vertical margin to prevent edge clipping

SettingsModal.tsx:

• Changed container to use lex-1 overflow-hidden instead of fixed max-height
• Content area already has overflow-y-auto for scrolling

Result

• Settings content now scrolls properly when needed
• Modal never clips at viewport edges
• Works correctly on any window size

Testing

• ✅ Build passes
• ✅ All unit tests pass (395/395)
• ✅ Manually tested with small window - no clipping
• ✅ Manually tested with long content - scrolls properly

Before:

After: