Decouple reschedule assessment interval

[colonelpanic8]

Summary

• make rescheduling check daily by default while preserving weekly/monthly assessment intervals for streaks and graphs
• evaluate reminder due-ness against the real assessment window, so weekly quota habits reschedule tomorrow until the current week target is met
• keep :reschedule-assessment-interval as an advanced override for non-daily reminder checks
• wire reschedule cadence, threshold, and day restrictions through CONFIG and legacy scattered properties
• document the default weekly-streak/daily-catch-up behavior

Validation

• just test
• just check

[colonelpanic8]

Fixes #8