Joseph Doherty
7f5d959fb9
Every dialect projects IS_NULLABLE and nothing read it. The browse session now reads it (tolerantly: a dialect that does not project it reads as unknown) and the picker's descriptor line says 'nullable' / 'NOT NULL', so an operator knows a cell can come back NULL (Uncertain, or Bad under nullIsBad) before committing the tag. The runtime catalog loader keeps reading names only - nothing at runtime consumes nullability. Refs #744 Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT