Show relative timestamps in trade history

[john-a-zoidburg]

Summary

• Show a relative age for every trade (5m ago, 3h ago, 2d ago) instead of exposing the less immediately useful block number.
• Keep each venue/time label linked to the existing xcp.io transaction page, with the exact UTC time and block available on hover.
• Refresh relative ages once per minute while the Trades tab is open.
• Remove the slight desktop horizontal overflow without changing the section width or the intentional mobile scrolling behavior.

Why

Trade timestamps answer the question most visitors have—“when did this happen?”—without requiring them to interpret a block height. The Counterparty match data and launch-room payload already carry each trade's block timestamp, so this is a presentation-only change with no additional requests or backend work.

The table also had a 43rem minimum width inside a 42rem section, which guaranteed a small horizontal scrollbar on desktop. Lowering the table's minimum to 41rem lets w-full match the section while preserving horizontal scrolling on narrow screens.

Screenshots

Before — block numbers and slight horizontal overflow

After — relative trade ages and corrected width

Verification

• npm run check — 200 tests plus web/API TypeScript, ESLint, and numeric-discipline checks
• npm run build --workspace apps/web