hours: move Prime's test MONDAY off a date the June pull now owns

June's sanctoral pull assigned Ss. Vitus, Modestus, and Crescentia to
2026-06-15 — the same date prime.test.ts's MONDAY constant used, which
correctly flips Prime's capitulum/Preces from ferial to feast form now
that isSundayOrFeast sees a real sanctoral winner there. Moved to an
still-unpulled October Monday instead; also fixed a stale comment that
had drifted from the constant's actual value.

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

tests/hours/prime.test.ts

@@ -1,11 +1,14 @@
 import { describe, expect, it } from 'vitest';
 import { resolveOrdo } from '../../src/hours';
 
-// 2026-08-10 is a Monday — the Monastic 1617 distribution gives Monday three
-// whole psalms (1, 2, 6), the first of which (Psalm 1) has real sample
-// content in data/psalms/001.yml, so these tests can check real verse data
-// without needing every psalm authored.
-const MONDAY = '2026-06-15';
+// 2026-10-05 is a Monday, and (as of the pre-1955 sanctoral pull reaching
+// October) still ordinary/ferial — the Monastic 1617 distribution gives
+// Monday three whole psalms (1, 2, 6), the first of which (Psalm 1) has
+// real sample content in data/psalms/001.yml, so these tests can check
+// real verse data without needing every psalm authored. Already had to
+// move once (from a June Monday that got real sanctoral content) — if a
+// future month's pull lands here too, it'll need to move again.
+const MONDAY = '2026-10-05';
 const SUNDAY = '2026-08-09';
 
 describe('resolveOrdo("prime", ...)', () => {