Track a transferred saint's origin date on DayWinner and Commemoration

Adds transferredFrom to both DayWinner's sanctoral variant and
Commemoration's sanctoral variant, set in calendar/index.ts's
applyIncomingTransfer whenever a transferred-in candidate actually lands
(wins outright) or ends up merely commemorated (lost a collision, or fell
below the landing day's own threshold) — previously this signal was
discarded after resolveDay used it once to decide the winner, so nothing
downstream could tell a transferred feast apart from a native one.

Also adds transferredAway to LiturgicalDay, set from a date's own native
occurrence when its candidate couldn't be kept there at all, so a UI can
note "this office moved elsewhere" without asserting a specific landing
date (which a later, unmodeled multi-hop chain — e.g. into Holy Week —
could get wrong).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013g7AsSvMD9oazR17f3BxLz

tests/calendar/september-sanctoral.test.ts

@@ -28,6 +28,7 @@ describe('September sanctoral pull (first pass)', () => {
       name: 'St. Raymond Nonnatus, Confessor',
       nameLa: 'Sanctus Raymundus Nonnatus, Confessor',
       rank: 'semiduplex',
+      transferredFrom: '2025-08-31',
     });
     expect(day.commemorations).toEqual([
       { kind: 'sanctoral', id: 'ss-twelve-brothers', name: 'Ss. Twelve Brothers, Martyrs', nameLa: 'Duodecim Fratres, Martyres', rank: 'simplex' },