* fix: correct bi-weekly recurring task scheduling for multi-day patterns
Fixes#1004
Previously, when a recurring task was set to repeat every N weeks (where N > 1)
on multiple weekdays that span a week boundary (e.g., Saturday + Sunday), the
algorithm incorrectly calculated the next occurrence dates.
The issue was in the calculateWeeklyRecurrence function, which didn't properly
determine when to add the interval skip for multi-weekday patterns. It would:
- Correctly handle Sat -> Sun (adjacent days, same cycle)
- Incorrectly handle Sun -> Sat (should skip weeks, but didn't)
This fix improves the logic to:
1. Detect when the current day is the last weekday in the pattern cycle
2. Account for Sunday (day 0) wrapping around in the day-of-week numbering
3. Only add interval skips when truly moving to a new cycle, not when moving
between weekdays within the same cycle
Test coverage added for:
- Bi-weekly Saturday + Sunday pattern (the reported bug)
- Starting from different days in the pattern
- Bi-weekly Tuesday + Thursday pattern
- Tri-weekly Friday + Saturday + Sunday pattern
* docs: update MEMORY.md with GitHub template requirements
- Add detailed PR template requirements and structure
- Expand bug report template requirements with all fields
- Update last modified date
