Plan proposal card: action buttons layout breaks when the Plan side panel is wide (narrow middle pane)

Description

The action-button row in the plan proposal card does not adapt to the available horizontal space in the middle (chat) pane. When the Plan side panel on the right is opened and made reasonably wide, the middle pane becomes narrow, and the whole button layout in the plan proposal card breaks:

<img width="3392" height="2202" alt="Image" src="https://github.com/user-attachments/assets/122e10dd-c31e-4cf8-a87d-fced29586091" />

• The static Reject / Revise… / Accept row stays at its full width.
• The floating "Accept and auto mode ⌘⏎" CTA stays anchored to the bottom-right of the card.
• Because the card is now too narrow, the floating CTA visually collides with the Accept button, partially obscuring it and making the click target ambiguous.

The root cause is layout, not the floating CTA itself — at narrow widths the entire bottom row needs to reflow (wrap, stack, shrink, or reposition the floating CTA).

Steps to reproduce

1. Open the Claude Code desktop app on macOS.
2. Open a session where Claude proposes a plan (any non-trivial task that triggers plan mode).
3. Open the right-hand Plan side panel.
4. Drag its divider so the Plan panel is reasonably wide (e.g. ~⅓ of the window) and the middle chat pane becomes correspondingly narrow.
5. Look at the plan proposal card at the bottom of the middle pane.

You will see the Accept and auto mode ⌘⏎ floating button overlapping the Accept button. With the Plan panel closed or narrow, the layout looks fine — the bug only appears under the squeezed-middle-pane condition.

Expected behavior

The bottom action row of the plan proposal card should remain readable and clickable at any reasonable width of the middle pane. Options:

• Wrap/stack the static buttons (Reject, Revise…, Accept) onto a second line when horizontal space is insufficient.
• Reposition the Accept and auto mode CTA (e.g. above the card, or as a split-button dropdown on Accept) so it never overlaps the static buttons.
• Apply a min-width constraint on the card or reflow the whole proposal card to a vertical layout at narrow widths.

No two interactive elements should overlap regardless of how the user sizes the side panels.

Actual behavior

At narrow middle-pane widths (caused by a wide Plan side panel), Accept and auto mode ⌘⏎ is rendered on top of Accept. The right edge of Accept is hidden, and which control fires on click in the overlap region is ambiguous.

Environment

• App: Claude Code desktop app (macOS)
• OS: macOS (Darwin 25.5.0)
• Plan: Max
• Model in session: Opus 4.7 (1M context)
• Reproducibility: deterministic — happens every time the middle pane is narrowed below the card's comfortable width