Add chat history review in session detail view

## Task Add a chat history review interface for operators and admins to view chat transcripts after a session has ended. ## UI Location In `SessionDetailComponent`, add a collapsible section (similar to timeline) showing chat history: ```haml .card.bg-base-200 .card-body %button.card-title История чата .chat-history - @session.support_session_messages.chronological.each do |msg| .chat{ class: msg.operator? ? 'chat-end' : 'chat-start' } .chat-header= msg.participant_name .chat-bubble= msg.content %time= msg.created_at ``` ## Features 1. **Chronological Display**: Messages in order with timestamps 2. **Participant Distinction**: Visual difference between operator/guest messages 3. **Collapsible**: Collapsed by default, expandable 4. **Empty State**: "No messages in this session" if empty ## Optional Enhancement - Download transcript button (plain text or JSON export) - Filter by participant ## Files to Modify - `app/components/remote_support/session_detail_component.rb` - `app/components/remote_support/session_detail_component.html.haml` - `spec/components/remote_support/session_detail_component_spec.rb`