Replace the stubbed chat API with a real WebSocket hook that
connects to /ws/chat and supports DM creation, messaging,
session join/leave, and history retrieval. Keep REST stub
functions for backward compatibility with existing pages
that require listChatSessions/getChatSessionById imports.
Replace removed fields with available data sources throughout UI:
- order pages: use service.title instead of consumer/player names
- chat: look up sender from session.participants, remove readonly
- community: simplify post cards, keep pinned icon
- post detail: keep pinned/linkedOrderId display
- shop rules: use string commissionValue
- dashboard: parse string amounts for income display
- dispute/review: remove initiator/avatar references
zetaloop