[BUG] Leaving mouse stationary underneath autocomplete items selects them on every keystroke

[JosXa]

Autocomplete menus (@ and / in TUI) and dialog select components currently auto-select items when UI elements move under a stationary cursor. This creates two problematic scenarios:

1. Menu appears under stationary cursor: When a menu opens, if the user's mouse happens to be over where an item renders, that item gets selected immediately even though the user hasn't moved the mouse
2. Filter changes reorder items: When typing to filter, items shift position and if one lands under the stationary cursor, it gets auto-selected, breaking keyboard navigation

Users expect hover selection to activate only on intentional mouse movement, not when UI elements move under a stationary cursor.

mouse-highlight-bug.mp4

[github-actions]

This issue might be related to existing issues. Please check:

• Slash command autocomplete selection jumps randomly when navigating #7814: Slash command autocomplete selection jumps randomly when navigating - addresses similar autocomplete selection problems, though this focuses on keyboard navigation rather than hover selection