Phase 2: app-code population of actor columns

Phase 2 (coder-pluto-cc): populate the new actor columns at every write call-site — server actions set createdBy on INSERT, updatedBy on UPDATE, deletedBy on soft-delete, via the shared mutation wrapper + archive-context. Depends on phase 1 columns existing. Behavioral change, Class-A (touches identity/clinical write paths). EVO-57 audit-trail schema program; plan authored by coder-pluto-cc from PLUTO-580 gap report (db-pluto-cc). Elazar-gated before DDL.