hours: add the day's-collect resolver

Terce/Sext/None's Oratio is the day's own Proper-of-season/-saints
collect, not a fixed text — getDayCollect() resolves it from the
LiturgicalDay's winner (temporal id or sanctoral saint's propers),
falling through to an honest "missing" status for saints that don't
have authored propers yet.

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

tests/hours/resolve-common.test.ts

@@ -0,0 +1,27 @@
+import { describe, expect, it } from 'vitest';
+import { resolveDay } from '../../src/calendar';
+import { getDayCollect } from '../../src/hours/resolve-common';
+
+describe('getDayCollect', () => {
+  it('resolves a real, verified collect for an ordinary Sunday', () => {
+    const day = resolveDay('2026-08-09'); // post-pentecost-11
+    const collect = getDayCollect(day);
+    expect(collect.status.la).toBe('verified');
+    expect(collect.status.en).toBe('verified');
+    expect(collect.text.en).toContain('Let us pray.');
+  });
+
+  it('resolves a real, verified collect for a ferial day via its governing Sunday', () => {
+    const day = resolveDay('2026-06-14'); // post-pentecost-03's Sunday
+    const collect = getDayCollect(day);
+    expect(collect.status.la).toBe('verified');
+  });
+
+  it('resolves as honestly missing for a saint with no authored propers yet', () => {
+    const day = resolveDay('2026-08-10'); // St. Lawrence wins outright, propers: null
+    expect(day.winner.kind).toBe('sanctoral');
+    const collect = getDayCollect(day);
+    expect(collect.status.la).toBe('missing');
+    expect(collect.status.en).toBe('missing');
+  });
+});