Refactor Matins psalmody overrides to category-keyed data

Split the store into categories/*.yml (generic Common-category psalm-
number/versicle/canticle scheme) and saints/*.yml (per-saint proper
antiphon overrides, unchanged shape) per the mechanism's own flagged
next step. St. Lawrence's file moves into saints/ with a category
cross-reference; resolution behavior (per-saint lookup, ferial
fallback when unauthored) is unchanged.

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

src/hours/matins-psalmody-overrides.ts

@@ -1,29 +1,35 @@
-/** Matins' own analogue of hours/lauds-psalmody-overrides.ts, but keyed
- * by Common category rather than per-saint: live-verified (see
- * data/hours/matins-psalmody-overrides/st-lawrence.yml's own header)
- * that the psalm *numbers* for Nocturns 1-2 are shared across saints of
- * the same Common category (a plain-Duplex Martyr and a plain-Duplex
- * Martyr-Bishop share all but one of the same twelve psalm numbers) —
- * only the antiphon text varies, proper to the individual saint when
- * authored, generic Common-of-* text otherwise. Deliberately the
- * opposite indexing choice from Lauds' own per-feast override (see that
- * file's own doc comment) — Lauds' 5-antiphon pool is shared across
- * every Duplex-majus+ feast regardless of category, so per-feast is the
- * natural key there; Matins' pool varies *by* category, so per-category
- * is the natural key here.
+/** Matins' own analogue of hours/lauds-psalmody-overrides.ts. Two data
+ * stores, both keyed by id:
+ *
+ * - `data/hours/matins-psalmody-overrides/categories/*.yml` — the
+ *   generic Common-of-* Matins psalmody (psalm numbers, versicles,
+ *   canticle refs, and the plain Common antiphon text), one file per
+ *   `SaintRecord.common` category. Live-verified against a saint with no
+ *   proper antiphon of his own (so his own output *is* the category
+ *   default) — see e.g. `categories/common-of-a-martyr.yml`'s own doc
+ *   comment. Reference/documentation content only: not consulted by
+ *   `getMatinsPsalmodyOverride` below, per this project's "stay on the
+ *   ferial fallback until proper antiphon text is authored per-saint"
+ *   decision (2026-08) — a saint without their own entry in `saints/`
+ *   still falls all the way back to matins.ts's own plain ferial table,
+ *   never to a category's generic antiphon text. Recorded so the next
+ *   saint authored in an already-proven category doesn't have to
+ *   re-derive/re-verify the same shared psalm numbers and versicles.
+ *
+ * - `data/hours/matins-psalmody-overrides/saints/*.yml` — real proper
+ *   antiphon text for one specific saint (only authored where a saint
+ *   genuinely has proper text of their own, confirmed against the live
+ *   engine, not merely inherited Common text). Each carries its own
+ *   `category` field cross-referencing the file above, but is otherwise
+ *   fully self-contained (own psalm numbers, not merged with the
+ *   category file at load time) — a saint's proper psalmody occasionally
+ *   swaps one slot's psalm number from the category default too (see
+ *   `saints/st-lawrence.yml`'s own note), so per-saint files stay
+ *   authoritative rather than being computed as a diff.
  *
  * `id` is looked up against `hours/resolve-common.ts`'s
  * `resolveOfficeWinner(day).id` when it's sanctoral, exactly like every
- * other per-feast/per-category content lookup in this app — but the
- * `id` values populated so far are individual saint ids (St. Lawrence
- * proper), not Common-category ids, since only the live-verified proof
- * has been authored; extending this to a real Common-category key
- * (`common-of-a-martyr`, etc., matching `SaintRecord.common`) with
- * per-saint antiphon overrides layered on top is the deferred bulk-
- * content work (see TODO.md) — not built yet, so a saint without their
- * own entry here falls back to the plain ferial weekday table
- * (matins.ts's own fallback), not to some other saint's proper
- * antiphons. */
+ * other per-feast/per-category content lookup in this app. */
 export interface MatinsPsalmodyGroup {
   psalms: number[];
   antiphon: Partial<Record<string, string>>;
@@ -40,22 +46,42 @@ export interface MatinsPsalmodyNocturn {
   versicle: { v: Partial<Record<string, string>>; r: Partial<Record<string, string>> };
 }
 export interface MatinsPsalmodyOverride {
+  id: string;
+  category?: string;
+  nocturn1: MatinsPsalmodyNocturn;
+  nocturn2: MatinsPsalmodyNocturn;
+  nocturn3: MatinsPsalmodyNocturn;
+}
+export interface MatinsPsalmodyCategory {
   id: string;
   nocturn1: MatinsPsalmodyNocturn;
   nocturn2: MatinsPsalmodyNocturn;
   nocturn3: MatinsPsalmodyNocturn;
 }
 
-const modules = import.meta.glob<{ default: MatinsPsalmodyOverride }>(
-  '../data/hours/matins-psalmody-overrides/*.yml',
+const saintModules = import.meta.glob<{ default: MatinsPsalmodyOverride }>(
+  '../data/hours/matins-psalmody-overrides/saints/*.yml',
+  { eager: true },
+);
+const categoryModules = import.meta.glob<{ default: MatinsPsalmodyCategory }>(
+  '../data/hours/matins-psalmody-overrides/categories/*.yml',
   { eager: true },
 );
 
 const overrides = new Map<string, MatinsPsalmodyOverride>();
-for (const mod of Object.values(modules)) {
+for (const mod of Object.values(saintModules)) {
   overrides.set(mod.default.id, mod.default);
 }
 
+const categories = new Map<string, MatinsPsalmodyCategory>();
+for (const mod of Object.values(categoryModules)) {
+  categories.set(mod.default.id, mod.default);
+}
+
 export function getMatinsPsalmodyOverride(id: string | undefined): MatinsPsalmodyOverride | undefined {
   return id ? overrides.get(id) : undefined;
 }
+
+export function getMatinsPsalmodyCategory(id: string | undefined): MatinsPsalmodyCategory | undefined {
+  return id ? categories.get(id) : undefined;
+}