Add nameLa mechanism for bilingual header, proof set of 11 feasts + St. Lawrence

Threads an optional nameLa field through SanctoralIdentity/SaintRecord/
TemporalFeastRecord/ActiveOctave so day-label.ts can render real Latin
proper names instead of always falling back to English. Authors the
proof set: all 11 named temporal feasts plus St. Lawrence (chosen to
exercise the octave-headline and octave-commemoration code paths too).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EwsZQMjALCvy7u9tFDWmuQ

src/calendar/temporal-feasts.ts

@@ -30,6 +30,9 @@ export type MovableAnchor =
 export interface TemporalFeastRecord {
   id: string;
   name: string;
+  /** Latin form of `name`, when authored — see calendar/types.ts's
+   * `SanctoralIdentity.nameLa` doc comment for the display fallback. */
+  nameLa?: string;
   octave?: OctaveConfig;
   rank?: FeastClass;
   anchor?: MovableAnchor;