prescriptions — overview

Country-agnostic clinical prescription pad (issue #269). Drafts with free-text medication lines (catalog autofill when medication_catalog is installed), issue/cancel lifecycle with frozen prescriber snapshot, favorite-combo templates, allergy/interaction safety banner, and PDF download/print.

Legal/format requirements per country ship as localization modules on top (same pattern as billing → verifactu): they implement PrescriptionComplianceHook and register for their country_code. No email delivery in v1.