Reuses the existing per-variety crop-calendar masks (sow/transplant/
flowering/fruiting/seed-harvest) — no schema change, no migration — to
answer "qué toca este mes" across the whole inventory. Since the months
are the grower's own record, there's no hemisphere assumption.
- Repo: CalendarEntry + watchCalendar() (varieties with any recorded
phase); VarietyListItem now carries sowMonths.
- Dedicated CalendarScreen (/calendar): a month strip (defaults to the
current month, intl month names) and varieties grouped by phase —
actions (sow/transplant/harvest seed) above informational (flowering/
fruiting), each tinted, tap → variety detail; empty-month state.
- Inventory filter: a 'this month' chip (shown only when some variety
has a calendar) keeps what sows in the current month; folded into the
attributes group + clear-filters.
- Entry points: a live Home card + a drawer item.
- i18n calendar block + menu.calendar (en/es/pt/ast).
- Tests: calendar_test (watchCalendar, list carries sow-months, pure
filter), calendar_screen_test (phase grouping, month switch, empty),
plus the screen added to the small-screen overflow guard.
