Import calendar-month/week Matins Nocturn 2 content for Aug-Nov

The later post-Pentecost Sundays' real Nocturn 2 patristic content isn't
keyed by Pentecost offset in the reference engine — it's keyed by civil
calendar month/week (the old "Scriptura occurrens" cycle), which shifts
relative to post-pentecost-NN every year depending on Easter's date. Port
Date.pm's monthday() algorithm (pre-1955/Tridentine rubrics) as a new,
date-driven id, author all 20 August-November month-week files from the
reference engine's Tempora/0MN-0.txt sources, and pool them in
hours/matins.ts as a third, independent reading source alongside the
existing temporalId lookup.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EWzE3kaSZCs79fPBrrE1aF

src/calendar/index.ts

@@ -349,6 +349,7 @@ export function isSundayOrFeast(day: LiturgicalDay): boolean {
 export { compareFeastClass, isAtLeast, decideOccurrence, minimumOutrightWinningRank } from './commemorations';
 export { resolveCollision } from './collision';
 export { resolveTemporalId } from './temporal-id';
+export { monthWeekId } from './month-week-id';
 export { activeOctavesFor, strictestThreshold, resolveActiveOctave, octaveGoverningPrivilegedDay } from './octaves';
 export type { ActiveOctave } from './octaves';
 export type {