Session field column-presence fixes are solid. Presentation lookup no longer
requires presentation_name to find existing records. Presenter gate broadened
to run lookup even without explicit code. Presenter INSERT still broken —
reverted field changes after IntegrityError issue; email-only column guard kept.
Do not rely on this state for presenter creation. Needs rework from c9c69ec.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>