Add show_in_registration and registration_description columns to festival_sections.
Registration form now shows deduplicated sections by name (across sub-events),
filtered by show_in_registration=true, grouped by category with card-based UI.
Section preferences use section_name instead of section_id.
Add GET/PUT registration-settings endpoints for festival-level bulk management.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Implements enterprise-grade identity resolution (detect → suggest → confirm)
for Person ↔ User linking. Matches are detected automatically on person
creation and user account creation, then surfaced to organisers for explicit
confirmation or dismissal. No silent auto-linking.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
