Command palette: compact rows with icons, recent items, contextual actions, fuzzy matching, shortcut hints

Part of PAR-357.

Problem (DS/CommandPalette, ui/lib/search.ts)

• Rows are huge. Each is about 100px tall, two lines ("Issues / Go to page"), with a chevron and no icon, so only 5 items fit in a large dialog. "Go to page" repeats on every row.
• Navigation only. "New issue" is a link to a page; there are no actions.
• Matching is weak. It's substring per word, not fuzzy (CommandPalette.tsx:26-29).
• No recents. No recently viewed issues or projects.
• Not contextual. On an issue page it offers nothing for that issue (change status, assign, copy ref…).
• Wasted chrome. The header "Search and commands" plus Esc label takes up space.

Reference

• Vapi: dense rows with icons, Actions / Recent / All pages groups and a shortcut on the right (Mobbin).
• Gumloop: create actions first, then entities (Mobbin).
• Superhuman: every action shows its shortcut, which teaches the keyboard model (Mobbin).

Do

• Use 36px single-line rows: icon, label, muted context (e.g. "Hibernia Economy"), and a right-aligned Kbd shortcut.
• Empty state: Recent (last 5 issues/projects), then Actions (New issue C, Change theme, Copy current URL), then Navigation.
• On an issue page: contextual actions first (Change status ▸, Assign ▸, Set priority ▸, Add label ▸, Copy ref, Archive), as nested pages inside the palette.
• Use fuzzy ranking (e.g. cmdk-style scoring). Search results show issues with status icon, ref and title.
• Remove the header bar; keep the footer hints.