Add onboarding_dismissed and branding columns (logo_data, logo_content_type, company_display_name) to users and teams models. Create SessionSupportingData model for attaching text snippets and screenshots to sessions. Add Pydantic schemas for onboarding status, branding responses, and supporting data CRUD. Update SessionExport to accept pdf format. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>