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/april-sanctoral.test.ts

@@ -45,7 +45,14 @@ describe('April sanctoral pull (first pass)', () => {
     ]);
 
     const monday = resolveDay('2029-04-30');
-    expect(monday.winner).toEqual({ kind: 'sanctoral', id: 'st-robert', name: 'St. Robert, Abbot', nameLa: 'Sanctus Robertus, Abbas', rank: 'duplex' });
+    expect(monday.winner).toEqual({
+      kind: 'sanctoral',
+      id: 'st-robert',
+      name: 'St. Robert, Abbot',
+      nameLa: 'Sanctus Robertus, Abbas',
+      rank: 'duplex',
+      transferredFrom: '2029-04-29',
+    });
     expect(monday.commemorations).toEqual([
       { kind: 'sanctoral', id: 'st-peter-martyr', name: 'St. Peter Martyr, Martyr', nameLa: 'Sanctus Petrus Martyr, Martyr', rank: 'semiduplex' },
     ]);

tests/calendar/november-sanctoral.test.ts

@@ -85,6 +85,7 @@ describe('November sanctoral pull (first pass)', () => {
       name: 'St. Clement I, Pope and Martyr',
       nameLa: 'Sanctus Clemens I, Papa et Martyr',
       rank: 'semiduplex',
+      transferredFrom: '2025-11-23',
     });
     expect(followingDay.commemorations).toEqual([
       { kind: 'sanctoral', id: 'st-chrysogonus', name: 'St. Chrysogonus, Martyr', nameLa: 'Sanctus Chrysogonus, Martyr', rank: 'simplex' },

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' },

tests/calendar/transfer.test.ts

@@ -28,7 +28,14 @@ describe('transfer mechanism (resolveDay integration)', () => {
       rank: 'semiduplex',
     });
     expect(saturday.commemorations).toEqual([
-      { kind: 'sanctoral', id: 'vigil-of-st-lawrence', name: 'Vigil of St. Lawrence', nameLa: 'Vigilia Sancti Laurentii', rank: 'vigil' },
+      {
+        kind: 'sanctoral',
+        id: 'vigil-of-st-lawrence',
+        name: 'Vigil of St. Lawrence',
+        nameLa: 'Vigilia Sancti Laurentii',
+        rank: 'vigil',
+        transferredFrom: '2026-08-09',
+      },
     ]);
 
     // The Sunday's own winner is unaffected by the vigil, but St. Romanus