Model Ascension, Corpus Christi, and the Sacred Heart as temporal feasts

Adds pre-1955 TemporalFeastRecords (rank duplex-1-classis, real octaves)
for the three "feasts of the Lord" that were previously only referenced
as bare date offsets: Corpus Christi/Sacred Heart's own days already
couldn't lose to a sanctoral candidate, but with no record the day fell
back to the generic Trinity-week feria collect and never displayed its
real name; Ascension had no protection at all against an ordinary saint
winning it outright. Sacred Heart's own record carries the
forbidsSuccessorCommemoration flag added in the prior commit, refusing to
commemorate Most Precious Blood on the rare late-Easter date they fall
adjacent.

octave.wins is set to duplex on all three, matching Pentecost's own
verified threshold, despite a known conflict with a previously
live-verified case (St. Ubald winning First Vespers within Ascension's
own octave) -- kept per direct instruction; the affected tests (Ubald,
St. Margaret of Scotland) were updated to assert the new behavior, and
the tradeoff is documented in ascension.yml and TODO.md. A handful of
unrelated test fixtures that happened to land inside these new octave
windows were moved to nearby clean dates.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014axryJBrRswYh2niA7WCUc

src/calendar/temporal-feasts.ts

@@ -85,7 +85,12 @@ export function movableTemporalFeasts(): TemporalFeastRecord[] {
 const FIXED_DATE_STARTS: [string, string][] = [['12-25', 'christmas-day']];
 
 /** Easter-offset starts (offset -> temporal feast id). */
-const EASTER_OFFSET_STARTS: [number, string][] = [[49, 'pentecost-sunday']];
+const EASTER_OFFSET_STARTS: [number, string][] = [
+  [39, 'ascension'],
+  [49, 'pentecost-sunday'],
+  [60, 'corpus-christi'],
+  [68, 'sacred-heart'],
+];
 
 /** Which temporal feast(s), if any, have their own (day-1) octave start on this date. */
 export function temporalFeastIdsStartingOn(isoDate: string): string[] {