PhoenixKit V35 Migration: Support Tickets System

Adds complete customer support ticket system with status workflow, comments with internal notes, file attachments, and audit trail.

Changes

Tickets Table (phoenix_kit_tickets)

• Main ticket storage with status workflow (open/in_progress/resolved/closed)
• Customer user association (who created the ticket)
• Handler assignment (support staff)
• Denormalized comment counter
• Resolved/closed timestamps for tracking

Ticket Comments (phoenix_kit_ticket_comments)

• Threaded comments with internal notes support
• is_internal flag for staff-only visibility
• Self-referencing for nested replies

Ticket Attachments (phoenix_kit_ticket_attachments)

• Junction table for files on tickets or comments
• Position-based ordering with captions

Ticket Status History (phoenix_kit_ticket_status_history)

• Complete audit trail for all status changes
• Who changed, from/to status, optional reason

Settings

• Module config: enabled, per-page
• Feature toggles: comments, internal notes, attachments
• Workflow: allow reopen

Features

• UUIDv7 primary keys for time-sortable IDs
• Comprehensive indexes for efficient queries
• Foreign key constraints for data integrity
• Check constraint for attachment parent reference