calendar: split privileged-feria into two real precedence tiers

A plain Duplex saint was losing to any privileged feria (Ember days
included) since the occurrence engine only let duplex-1-classis+ get
even a commemoration there. Verified this was wrong: St. Gregory the
Great, plain Duplex, outright wins against a Lenten Ember Saturday in
the real Monastic 1617 engine.

Splits TemporalCategory's single privileged-feria into privileged-feria
(the lesser tier — Lent's Ember days, verified — now behaves like an
ordinary Sunday: Duplex+ wins outright) and privileged-feria-major (Ash
Wednesday, Holy Week, the Easter Octave, verified via St. Mark only ever
being commemorated there, never winning — behaves like privileged-
Sunday). Everywhere else the old single category was ambiguous
(Pentecost's own Ember days/Vigil/Octave, the Vigil of Christmas)
defaults to the stricter major tier pending verification.

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

src/calendar/index.ts

@@ -48,12 +48,14 @@ function applyIncomingTransfer(
   winner: DayWinner,
   commemorations: Commemoration[],
 ): DayWinner {
-  if (temporalCategory === 'privileged-feria') {
-    // Deferred: a transfer landing on a privileged feria (the concrete
-    // case is Holy Week, right after Palm Sunday) needs its own
-    // Easter-date-keyed lookup table, the same way the reference engine
-    // handles it — not modeled yet. The transfer is simply not delivered
-    // here rather than guessed at.
+  if (temporalCategory === 'privileged-feria-major') {
+    // Deferred: a transfer landing on one of these (the concrete case is
+    // Holy Week, right after Palm Sunday) needs its own Easter-date-keyed
+    // lookup table, the same way the reference engine handles it — not
+    // modeled yet. The transfer is simply not delivered here rather than
+    // guessed at. The lesser privileged-feria tier doesn't need this —
+    // ordinary collision/transfer logic is fine there, same as any
+    // ordinary-sunday landing.
     return winner;
   }
   if (winner.kind === 'temporal') {