Suggestion chips feel dead when prompt is scrolled off-screen

[fkb032]

Bug

Clicking a suggestion chip (e.g. Show all file extensions in Finder) seeds the prompt via seedPrompt, but if the input is off-screen the click looks like a no-op.

Expected

On seed: update text, scroll input into view, focus it. Do not auto-submit.

Fix at

seedPrompt in prompt-input.tsx (shared path for chips / trending / history).

Screenshot

[linear-code]

ENG-612