[Claudesaul]

Problem

Closing the right panel makes it look empty partway through. The closing edge wipes across the content from the left, so the file list is gone while the panel is still half open.

This came in with pingdotgg#26233, which pinned all of the panel's content to keep the tab bar out from under the title bar buttons. Only the tab bar needed that.

Change

Only the tab bar stays pinned now. Everything below it slides out with the panel again, as it did before pingdotgg#26233, and the tabs still stay clear of the buttons. Opening does the reverse. Maximized panels and the narrow-window sheet are unchanged.

Scope and approval

Small fix for an obvious visual regression from pingdotgg#26233: the panel goes blank while it closes.

Verification

• To reproduce: open the Files tab, set panel animations to 300ms and close the panel.
• Chromium on macOS at 1280×800 against the dev server: I froze the close at set points and measured it on main and on this branch. 23% of the way through, the panel edge is at 1036px. On main the content is still at 741px, so the edge has wiped over it. Here it's at 1037px, moving with the edge.
• The tab bar stays at 741px for the whole close on both, so the tabs never reach the buttons.
• Resizing, maximizing, restoring and the narrow-window sheet all keep the tab bar and content in the right place.
• vp test run apps/web/src/components/RightPanelTabs.test.tsx (10 passed); web typecheck and lint clean.
• Not checked: the Electron window, panel tabs other than Files, and running the narrow layout below 360px, where the content keeps main's right alignment.

Recording: a few opens and closes at regular speed, then one close and open zoomed in at quarter speed.

Before	After

Model: Claude Opus 5.5; harness: T3 Code.