v1.9.3 — remove highlight shimmer, fix tooltip dark mode

• Remove ambient shine animation from highlighted text entirely (keyframes, ::before pseudo-element, and JS custom property writes all gone)
• Fix hover tooltip always rendering in light mode: showTooltip() now stamps data-evident-dark directly on the tooltip element at show time instead of relying on the ancestor selector [data-evident-dark] .evident-tooltip, which could miss if the SET_DARK_MODE message hadn't arrived yet