Pecan v0.4.0

Pecan v0.4.0 adds a console view of the mint's keys and their expiry, a searchable activity history, and a Mint tab that shows its status first.

• Keys tab. A timeline shows every keyset: which one is issuing, since when, and when ecash issued under it expires. To issue ecash that expires (for example after a year), pick a lifetime and copy the matching cdk-mint-cli rotate-next-keyset command. The command needs [mint_management_rpc] on the mint, and cdk-mint-cli is not part of the mintd image. The checklist warns 30 days before the issuing keys expire and fails once they have expired.
• Activity tab. Settled history in pages of 25. You can search it, filter by kind, status and date, see paid totals for the selection, and export it as CSV. Tickets now record which console user settled or voided them.
• Bounded lists. The Teller shows 10 open quotes and 10 recent operations before a "Show all" or "Full history" link. The Overview chart has 7D, 30D, 90D, 1Y and All ranges.
• Mint tab. One status line, a five-step strip and the next step to take. The full checklist, the config snippet and the technical details are collapsible.
• Phone width. The console no longer scrolls sideways on a 390px screen.

The processor now writes keysets.json to its work directory to remember when each keyset was first seen. Keysets that existed before the update show "before ".

mintctl update --check   # preview
mintctl update           # console and processor; the mint pin is unchanged

The bundled mint stays on 0.18.0-rc.0.