Prime: real content (psalms, Martyrology, Regula) and ordo corrections

Pulls in verified content from Divinum Officium rather than placeholders:
17 psalms (2, 6, 7-19, 118, 129), 365 days of the Martyrology, and the full
121-reading Regula cycle, plus the Athanasian Creed.

Ordo corrections driven by review against the real engine output:
- Capitulum and Preces now pick a Sunday/feast vs. ferial form
  (calendar/isSundayOrFeast); ferial Preces said every ferial day by choice.
- Chapter responsory, hymn doxology, and the opening versicle's
  Alleluia/Laus tibi all vary by season via a shared resolver
  (hours/seasonal-propers.ts).
- Real Roman Kalends/Nones/Ides Latin dating (calendar/roman-date.ts,
  verified against 363/365 real Martyrology headings) plus the historical
  "bis sextus" Feb 29 handling, and the Martyrology's Luna (moon-day)
  heading (a ported Golden-Number calculation).
- Fixed responsory structure (was missing its initial full repeat),
  weekday psalm antiphons (opening as incipit-or-full by rank, full
  repeat after the psalms/Creed as its own part, "*" chant mark kept),
  scripture citations on the capitulum/lectio brevis, and V./R. markers
  switched from Unicode symbols to plain text for reliable font rendering.
- Dropped Pretiosa and the dead-commemoration psalm (129) for time;
  trimmed section headings down to the ones that are actually named
  things (Preces, Chapter Office, etc. no longer relabel connective text).

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

src/hours/seasonal-propers.ts

@@ -0,0 +1,29 @@
+import type { Season, OccurringFeast } from '../calendar/types';
+
+export interface SeasonalPropersTable {
+  perAnnum: string;
+  bySeason: Record<string, string>;
+  byFeastId?: Record<string, string>;
+}
+
+/**
+ * Shared by everything that picks a common-propers id by season with a
+ * per-feast override (the chapter responsory's verse, the hymn doxology,
+ * and presumably more once milestone 4 lands) — feast overrides win over
+ * season, which wins over the "per annum" default. `occurring` is always
+ * [] until milestone 4, so today this always returns a season match or
+ * perAnnum.
+ */
+export function resolveSeasonalPropersId(
+  season: Season,
+  occurring: OccurringFeast[],
+  table: SeasonalPropersTable,
+): string {
+  for (const feast of occurring) {
+    const override = table.byFeastId?.[feast.id];
+    if (override) {
+      return override;
+    }
+  }
+  return table.bySeason[season] ?? table.perAnnum;
+}