Right pane New Tab: layout A with hover-card PR rows

Layout A, with the PR list replaced by CloudPullRequestRow: the one-line rows from the cloud sidebar's PR hover card (state icon, #number, title, +/−). Rendered in the running dev app with real data. Left: default right-pane width. Right: the pane expanded (⌘⇧L).

A1. A's headings, hover-card PR rows

A2. Hover-card headings too

Every section title uses the hover card's CloudSection title (small, uppercase), so the whole screen reads like the card.

Before: A with the Pull requests view's rows

Still open

• Which PRs? Shown: the org's open PRs, newest first (what the Pull requests view lists). Alternatives: only PRs opened from Paradev, this workspace's repo, or only mine.
• Which pages? Shown: this workspace's pages. Alternative: all pages I can see.
• Hotkeys: ⌘T, ⌘⇧B and ⌘⇧G replace a focused New Tab in place. Files, Review and Pages have no hotkey yet.