From 768 px /settings shows mock 2e: the title, "Changes apply to everyone in the household." and sub-tabs Household, Regular dinners and Notifications & AI. Below 768 px the 1p list navigation is unchanged. - Notifications & AI: two columns. The left holds a neutral placeholder for the Notifications matrix and Google Chat webhook cards (Feature 19); the right holds the AI assistant card, the same form as /settings/ai with the system prompt growing to fill, and the Recipe search card. - Household embeds the /settings/household form. - Regular dinners is a placeholder until Feature 12 builds that screen. Tabs stay mounted while hidden so drafts survive switching, and one leave guard covers all of them. The AI and Household forms are split from their mobile page headers so both layouts render the same components. Maestro task: b0696e7d-63d5-42bb-9c09-19d1995a55cf Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>