Give the Matins ferial hymn its own text per weekday, not one for all

matins-hymn-ferial.yml turned out to already be Monday's own hymn
("Somno reféctis ártubus"), mislabeled as a single fixed year-round
text and used unconditionally for every weekday -- the source
(Psalterium/Special/Matutinum Special.txt) genuinely varies this hymn
Monday through Saturday, the classic "week of hymns". Caught first on
Friday ("Tu Trinitátis Únitas" expected, Monday's text shown), then
again on a real Ember Saturday ("Summæ Deus cleméntiæ" expected).

Authored matins-hymn-ferial-{tuesday,wednesday,thursday,friday,
saturday}.yml (Monastic 1617 text, live-verified against the CGI
instance directly, including Friday's own real M-track word-swaps) and
wired resolveMatinsHymn's final fallback tier to pick by day.weekday.
Sunday is left on the existing placeholder, documented as a real,
more complex not-yet-understood gap (a two-hymn source split).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AGjUyhUZJaSjiniEmnLdak

tests/hours/matins.test.ts

@@ -774,7 +774,9 @@ describe('resolveOrdo("matins", ...) Assumption-octave hymn fallback (2026-08-22
   });
 
   it("a plain ferial day outside the octave still gets the plain ferial hymn, unaffected", () => {
-    expect(hymnLatin(FERIAL_DATE)).toContain('Somno');
+    // FERIAL_DATE (2026-12-01) is a Tuesday -- see the identical note on
+    // the other FERIAL_DATE hymn assertion below.
+    expect(hymnLatin(FERIAL_DATE)).toContain('Consors patérni lúminis');
   });
 });
 
@@ -1072,7 +1074,11 @@ describe('resolveOrdo("matins", ...) Common-of-an-Apostle hymn + invitatory (202
   });
 
   it('a plain ferial day is unaffected -- still falls through to the plain ferial hymn and invitatory antiphon', () => {
-    expect(hymnLatin(FERIAL_DATE)).toContain('Somno');
+    // FERIAL_DATE (2026-12-01) is a Tuesday, so this is Tuesday's own
+    // ferial hymn ("Consors patérni lúminis") since 2026-09-04's weekday-
+    // specific hymn fix -- previously every weekday fell through to the
+    // same (mislabeled) Monday text ("Somno reféctis ártubus").
+    expect(hymnLatin(FERIAL_DATE)).toContain('Consors patérni lúminis');
     expect(invitatoryFullLatin(FERIAL_DATE)).toContain('Veníte');
     expect(invitatoryFullLatin(FERIAL_DATE)).not.toContain('Regem Apostolórum');
   });