Give Prime's Preces the ferial form on Vigil days

isSundayOrFeastOffice treats any sanctoral winner, Vigils included, as a
"feast," so a Vigil day was getting the Sunday/feast Preces. Add a
by-day-kind 'vigilIsFerial' flag, set only on Prime's Preces part (its
capitulum keeps the old behavior), so a Vigil-ranked winner now routes
to the ferial Preces text instead.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HWN869GrMFHqrer9fdCBbF

src/hours/prime.ts

@@ -97,10 +97,13 @@ function resolvePart(part: HourPart, date: string, day: LiturgicalDay): Resolved
     case 'canticle':
       return [{ kind: 'canticle', canticleId: part.canticleId, text: resolveCommon(part.textRef.id) }];
     case 'by-day-kind': {
-      if (part.omitOnDouble && isDoubleOrHigher(resolveOfficeWinner(day))) {
+      const winner = resolveOfficeWinner(day);
+      if (part.omitOnDouble && isDoubleOrHigher(winner)) {
         return [];
       }
-      const ref = isSundayOrFeastOffice(day) ? part.sundayOrFeastRef : part.ferialRef;
+      const isVigil = winner.kind === 'sanctoral' && winner.rank === 'vigil';
+      const useFeastForm = isSundayOrFeastOffice(day) && !(part.vigilIsFerial && isVigil);
+      const ref = useFeastForm ? part.sundayOrFeastRef : part.ferialRef;
       if (part.resolvedKind === 'preces') {
         return [{ kind: 'preces', text: resolveCommon(ref.id), label: part.label }];
       }

src/hours/types.ts

@@ -61,6 +61,12 @@ export type HourPart =
       resolvedKind: 'chapter' | 'preces';
       label?: string;
       omitOnDouble?: true;
+      // When true, a Vigil-ranked sanctoral winner takes the ferialRef
+      // instead of the sundayOrFeastRef isSundayOrFeastOffice would
+      // otherwise give it (that function treats any sanctoral winner,
+      // Vigils included, as a "feast"). Prime's Preces use this; its
+      // capitulum doesn't.
+      vigilIsFerial?: true;
       sundayOrFeastRef: PropersRef;
       ferialRef: PropersRef;
     }