Add Paschaltide-variant fallback for minor-hour Commons

Confirms and formalizes what TODO.md had flagged as an open question:
the reference engine's own source has explicit Paschaltide variants
(Commune/C1p.txt, C2p.txt, C3p.txt -- "tempore Paschali") for exactly 3
of its 12 Common categories -- Apostles, a Martyr-Bishop, Several
Martyrs -- a real liturgical restriction of Alleluia/victory imagery to
apostles and martyrs, not a coincidence.

resolveMinorHourAntiphon/resolveMinorHourChapter now try a
`${minorHoursCommon}-paschaltide` variant first whenever day.season is
eastertide/ascensiontide/pentecost (the same three-season window as
Compline's own Regina Caeli table, since "tempore paschali" runs through
the Pentecost octave in both), falling back to the plain Common when no
variant is authored.

common-of-apostles-paschaltide (7 files) ported directly from the
reference engine's own Commune/C1p.txt source files rather than
live-queried, then cross-checked against st-mark's already-authored,
live-queried content -- identical except one antiphon's asterisk, which
the source places one word earlier; corrected to match. st-mark and
st-john-before-the-latin-gate's duplicate per-saint files removed
entirely; ss-philip-and-james's chapter files removed (its antiphons
stay proper).

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

src/data/calendar/saints/ss-philip-and-james.yml

@@ -6,3 +6,4 @@ name: "Ss. Philip and James, Apostles"
 rank: duplex-2-classis
 common: common-of-an-apostle
 propers: "ss-philip-and-james"
+minorHoursCommon: common-of-apostles

src/data/calendar/saints/st-john-before-the-latin-gate.yml

@@ -9,3 +9,4 @@ name: "St. John Before the Latin Gate"
 rank: duplex-majus
 common: common-of-an-apostle
 propers: "st-john-before-the-latin-gate"
+minorHoursCommon: common-of-apostles

src/data/calendar/saints/st-mark.yml

@@ -11,3 +11,4 @@ name: "St. Mark, Evangelist"
 rank: duplex-2-classis
 common: common-of-an-evangelist
 propers: "st-mark"
+minorHoursCommon: common-of-apostles