Spelling and grammar fixes across prayer components (e.g. sanctífica,
peccávi, nequítiam, Hoffnung, Menschen, Geheimnisse), merge cæ ligature
in Credo, restore traditional clause order and close Ps. citation in the
Prayer Before a Crucifix.
Add Guardian Angel, Apostles' Creed, Tantum Ergo, Angelus, and Regina
Caeli to the prayers collection. Move standalone Angelus route into the
prayers system with a 301 redirect from the old path. Extract Easter
computation into shared utility ($lib/js/easter.svelte.ts) and use it
for liturgical season awareness: during Eastertide the rosary defaults
to Glorious mysteries and swaps Salve Regina for Regina Caeli; during
Lent it defaults to Sorrowful mysteries. Seasonal badges shown on both
the mystery selector and prayer sections.