Supporting Surfaces

Right pane router

RightPaneView.swift keeps a picker plus four routed modes:

Pending Changes: DiffPaneView.swift runs /usr/bin/git status and numstat off the main actor, then shows branch, totals, and file rows.
Browser: BrowserPaneView.swift wraps a retained WKWebView, normalizes URLs/searches/local dev servers, and preserves history across mode changes.
Plugins: ExtensionsPageView.swift presents commands, prompt templates, and skills with tabs/search.
Archived Chats: lists retained archived sessions and removes the archive flag on restore.

BrowserModel and DiffModel are lazily instantiated by AppModel outside SwiftUI body evaluation and retained for app lifetime.
ExtensionsModel.swift launches a short-lived Pi client in the selected project and calls get_commands.
Supporting panes do not own or retarget the selected conversation runtime.

Settings currently persists appearance and Promote-to-Project defaults; model favorites are planned next.