Add 6 more February saints/feasts previously never added

Purification of the BVM (Feb 2), St. Andrew Corsini (Feb 4), St. John
of Matha (Feb 8), Apparition of the Immaculate BVM at Lourdes (Feb 11),
Ss. Seven Founders of the Servite Order (Feb 12), St. Gabriel of Our
Lady of Sorrows (Feb 27) -- all had real, complete Matins content in
the reference engine and no exclusion comment; simply never reached
during the earlier month-by-month sanctoral pulls. Continuing the same
sweep as January's St. Francis de Sales/St. Martina/St. John Bosco.

Test update (not a regression): St. Andrew Corsini transfers onto Feb 5
in years where Sexagesima falls on his own Feb 4, outranking St. Agatha
when it does -- february-sanctoral.test.ts's proof year for Agatha
moved from 2029 (now a collision year) to 2025 (clean).

npm test (365 tests) and tsc --noEmit both pass.

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

src/data/calendar/sanctoral-calendar.yml

@@ -47,18 +47,24 @@ days:
   # file), and Feb 29's leap-year redirect of the Vigil of St. Matthias
   # (a real but not-yet-modeled leap-day date-shift, see st-matthias.yml).
   "02-01": [st-ignatius-of-antioch]
+  "02-02": [purification]
   "02-03": [st-blaise]
+  "02-04": [st-andrew-corsini]
   "02-05": [st-agatha]
   "02-06": [st-dorothea]
   "02-07": [st-romuald]
+  "02-08": [st-john-of-matha]
   "02-09": [st-apollonia]
   "02-10": [st-scholastica]
+  "02-11": [apparition-of-the-immaculate-bvm]
+  "02-12": [ss-seven-founders-of-the-servite-order]
   "02-14": [st-valentine]
   "02-15": [ss-faustinus-and-jovita]
   "02-18": [st-simeon]
   "02-22": [chair-of-st-peter-at-antioch]
   "02-23": [vigil-of-st-matthias]
   "02-24": [st-matthias]
+  "02-27": [st-gabriel-of-our-lady-of-sorrows]
   # March — 3/12 of the pre-1955 pull. Same exclusions as before (fixed
   # BVM feast: Annunciation Mar 25). St. Benedict's own day (Mar 21,
   # Duplex I. classis, the highest rank in this set so far) has no