calendar: add Christ the King, last Sunday of October

A 1925 addition, so nowhere in the Monastic Tridentinum 1617 base this
project otherwise targets -- content sourced from "Monastic Divino
1930" instead, the Monastic-lineage version of the era that actually
carries it. Always wins outright (Duplex I. classis, confirmed live),
commemorating whichever Sunday after Pentecost it displaces -- same
additive-layering shape as applyOctaves/applyMarianSaturday, run last
so nested commemorations (e.g. a Simplex saint already commemorated
under that Sunday) survive underneath it.

Extended the Lauds psalmody-override mechanism (both the psalm groups
and, newly, the chapter/responsory/hymn/versicle bundle) to recognize
named temporal winners as unconditionally override-eligible, not just
duplex-majus+ sanctoral ones -- generalizing what had been a Marian-
Saturday-only special case. Suffrages needed their own explicit check
too: isDoubleOrHigher only ever looks at a sanctoral rank, and a named
temporal winner has no FeastClass to check at all.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/calendar/index.ts

@@ -1,6 +1,6 @@
 import type { Commemoration, DayWinner, LiturgicalDay, SanctoralIdentity, TemporalCategory } from './types';
 import { weekdayOf } from './weekday';
-import { resolveSeason, resolveTemporalCategory } from './temporal';
+import { resolveSeason, resolveTemporalCategory, sundayOnOrBefore } from './temporal';
 import { resolveTemporalId } from './temporal-id';
 import { getSanctoralCandidatesFor } from './feasts';
 import { decideOccurrence, isAtLeast, type OccurrenceResult } from './commemorations';
@@ -102,10 +102,41 @@ export function resolveDay(isoDate: string): LiturgicalDay {
 
   winner = applyOctaves(isoDate, winner, commemorations);
   winner = applyMarianSaturday(isoDate, weekday, temporalCategory, winner, commemorations);
+  winner = applyChristTheKing(isoDate, winner, commemorations);
 
   return { date: isoDate, weekday, season, temporalCategory, winner, commemorations };
 }
 
+/** The Sunday on or before Oct 31 — always lands in October since Oct 31
+ * is at most 6 days after the month's last Sunday. */
+function lastSundayOfOctober(year: number): string {
+  return sundayOnOrBefore(`${year}-10-31`);
+}
+
+/**
+ * Per direct instruction: the last Sunday of October is always Christ the
+ * King, full stop — unlike every other layer in this file, nothing here
+ * loses gracefully or gets a rank check; whatever was winning (a plain
+ * numbered Sunday after Pentecost in every ordinary year, but modeled
+ * generally in case a high-ranked sanctoral candidate is ever assigned to
+ * that date too) is demoted straight to a commemoration. Confirmed live
+ * (see data/calendar/temporal-feasts/christ-the-king.yml): Duplex I.
+ * classis, well above anything that could contest it under this
+ * project's own calendar.
+ */
+function applyChristTheKing(isoDate: string, winner: DayWinner, commemorations: Commemoration[]): DayWinner {
+  const year = Number(isoDate.slice(0, 4));
+  if (isoDate !== lastSundayOfOctober(year)) {
+    return winner;
+  }
+  if (winner.kind === 'temporal') {
+    commemorations.push({ kind: 'temporal', id: winner.id });
+  } else {
+    commemorations.push({ kind: 'sanctoral', id: winner.id, name: winner.name, rank: winner.rank });
+  }
+  return { kind: 'temporal', id: 'christ-the-king' };
+}
+
 /**
  * Layered on top of everything above, same spirit as applyOctaves: never
  * changes decideOccurrence's own rules, just relabels the result on a free