The settle-up form only exposed from/to/amount and silently dated the
payment by created_at, unlike a regular expense which has an editable
date. Add a settled_at column (independent of created_at, same split as
expense_date) through the schema, migration, service, REST and MCP
surfaces, and the desktop + mobile forms; the ledger groups a payment by
settled_at, falling back to created_at for rows recorded before the
column existed.
Closes#2151
The desktop Costs view mixes recorded settle-up payments into the day-grouped
expense ledger, but the mobile screen only ever fetched balances/flows and
silently dropped the settlements array the server already returns — a
recorded payment cleared the balance but then left no trace anywhere on
mobile.
Left out of the commits they belong to by hand, not by intent: the mobile
screen suites, the tripRepo cache-first read behind the startup-destination
fix, and the MSW handlers the stricter unhandled-request setting needs.
RemEx