[Bug] TUI toast notifications are obscured by sidebar — top-right position overlaps sidebar content #34295

Bug Description

Toast notifications in the TUI are rendered at position="absolute" top={2} right={2} (see packages/tui/src/ui/toast.tsx). When the session sidebar is visible (width=42, height=100%), it occupies the right side of the screen and its content (session title, workspace info, version footer) overlaps the toast upper half.

Users only see the bottom portion of toast messages. This affects all toast notifications, including:

• Plugin startup toasts (e.g., "OhMyOpenCode 4.13.0 Sisyphus is steering OpenCode on steroid")
• Plugin warning toasts (e.g., model compatibility warnings from oh-my-openagent)
• Copy-to-clipboard confirmations

Steps to Reproduce

1. Open a session in the TUI with the sidebar visible
2. Trigger any toast notification (e.g., start a session with a plugin that shows a startup toast, or copy text to clipboard)
3. Observe that only the bottom half of the toast is visible — the top portion is hidden behind the sidebar

Expected Behavior

Toast notifications should be fully visible regardless of sidebar state.

Environment

• OpenCode: 1.17.9
• OS: Windows 11 (WSL2 terminal)
• Terminal: Windows Terminal

Root Cause

packages/tui/src/ui/toast.tsx positions the toast at top={2} right={2}, which places it directly under the sidebar content area when the sidebar is expanded.

Suggested Fix

Move the toast to bottom={6} left={2} (bottom-left corner) where it won conflict with the sidebar or the prompt input area. Alternatively, dynamically adjust the toast right offset based on sidebar visibility/width.

I have a local commit ready with this fix: moved toast to bottom={6} left={2}.