fix(chat): render instant-page preview icons in the edit accessory panel

Render instant-page preview icons in the message-edit accessory panel text (renderInstantPagePreviewIcons), with text render insets so the glyphs aren't clipped and a matching frame offset. Nudge the self-destruct timer icon's vertical inset.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>