Optional scrolling-columns layout for the right panel (niri/PaperWM style)

[saphid]

Problem

The right panel shows one surface at a time. When I'm reviewing an agent's work I constantly flip between Diff, Terminal, Files and the Browser tab, and lose context each time. On a wide monitor (or with the panel maximized) there is plenty of room to keep two or three of them in view together.

Proposal

A client setting, Settings → Appearance → Right panel layout: Tabs (default, today's behavior, unchanged) or Scrolling columns.

In scrolling columns, the inline right panel lays every open surface out side by side on a horizontally scrolling strip, in the spirit of scrolling tiling window managers like niri / PaperWM:

• The existing tab bar stays as the overview. Selecting a tab scrolls its column into view; clicking inside a column selects its tab.
• One surface fills the panel; two or more share it in halves (min ~26rem each) and scroll past the edge.
• Native browser views only present while their whole column is in view, since they draw above the DOM and can't be clipped.
• Narrow windows (sheet presentation), the Pull Requests page, and mobile keep tabs.
• Each column keeps its own focus, shortcuts and terminal actions; only the selected column takes keyboard focus.

Scope is web/desktop client only: one contract field in client settings, a small RightPanelColumns component, and ChatView rendering each surface through one function instead of only the active one. No server or provider changes.

Ask

Is this a direction you'd accept as an opt-in setting? I have a working draft implementation with screenshots ((draft PR: #15949)), and I'm happy to narrow it (for example, drop the setting and only offer it while the panel is maximized) if you prefer.

[saphid]

Update after trying the first version: in Scrolling columns, the chat is now a column on the strip as well, instead of the strip living inside the right side panel. The conversation, Files, terminals, diff and browser sit side by side as equal columns you scroll through, closer to how niri and PaperWM work. Each panel column keeps its own tab header (close, tab menu, mute, rename). Tabs stays the default, and narrow windows keep the tab sheet.

Draft PR #15949 has the updated implementation and a real-time video: https://github.com/saphid/t3code/releases/download/pr-evidence-scrolling-panel-columns-20261005/scrolling-columns-v2.mp4

Still looking for a maintainer view on whether this direction fits before the PR leaves draft.