fix: Make selected task highlight use reverse video for accessibility (#11090)
Fix #10726
This PR improves the visibility of the selected task in the TUI by
switching the highlight style from color-only to reverse video
`(Modifier::REVERSED)`.
### Why
: The previous approach relied on foreground color, which was difficult
to perceive across popular terminal themes and especially for users with
color-vision deficiencies. Reverse video provides strong contrast that
is theme-agnostic and widely used in terminal UIs for accessibility.
### What changed:
In crates/turborepo-ui/src/tui/table.rs,
`.highlight_style(Style::default().fg(Color::Yellow))` →
`.highlight_style(Style::default().add_modifier(Modifier::REVERSED)).`
### Impact:
Visual only; no behavioral changes.
Improves UX for color-blind users (~8% of men, ~0.5% of women) and
anyone using low-contrast themes.
Co-authored-by: Anthony Shew <anthony.shew@vercel.com>