List conversation analytics

Per-conversation listing with per-row totals + first/last message timestamps. The inbox analog of GET /v1/analytics (posts listing) — same filter shape, same pagination, same sort/order semantics. Use as the entry point for the per-conversation analytics drawer at /v1/analytics/inbox/conversations/{conversationId}.

Rows are enriched with the conversation's participant info (participantName, participantUsername, participantPicture) and last-message preview by joining the Conversation document scoped to the caller's team. Max date range is 365 days.