Problem: Village cadence requires easy monthly/weekly repeats (e.g., staff lounge snacks).
Change:
- Add Recurrence to needs: frequency=[none|weekly|monthly], by_day, by_week, end_date.
- Auto‑generate upcoming instances and auto‑expire past instances.
- Champion can create one master need; system generates visible “current” instance.
Email UX: champions can highlight 2–3 current recurring items in follow‑ups.