b8586537f8
c63ec67 dropped diary_start_week_day, hardwiring the weekly diary to ISO
(Monday) weeks. Upstream vimwiki instead names a weekly note by the
week-start day's date (YYYY-MM-DD) and honours diary_start_week_day. Rather
than force one scheme, make it a per-wiki choice so migrators keep upstream
behaviour while existing nuwiki weekly files keep working:
- New per-wiki key `diary_weekly_style`: `iso` (default — `YYYY-Www`,
Monday-based, nuwiki's original) or `date`/`vimwiki` (`YYYY-MM-DD` of the
week-start day, upstream parity).
- Restored per-wiki key `diary_start_week_day` (`monday`..`sunday`, default
monday); applies only in `date` mode.
Implementation:
- nuwiki-core::date gains WeeklyStyle, WeekStart, and DiaryCalendar (owns
today/next/prev — date-mode snaps to the week-start and steps ±7 days;
iso/daily/monthly/yearly defer to the existing DiaryPeriod logic).
- WikiConfig gains the two fields (+ defaults, RawWiki, From) and a
diary_calendar() builder; commands.rs diary_open_relative and the
next/prev pivot use it.
Defaults preserve current behaviour (iso/monday), so no breaking change.
Tests: DiaryCalendar cases in nuwiki-core/tests/diary.rs (snap, ±7, sunday
start, iso delegation, daily) + config round-trip in
nuwiki-lsp/tests/index_and_config.rs. README + doc/nuwiki.txt + lua config
comment updated. fmt + clippy clean; all crate tests + config-parity green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>