GET /api/v1/channels/{id}/messages/{message_id}/thread authorized only the URL channel, but get_messages_by_parent_id() appended the thread parent (loaded by id) without checking it belonged to that channel, so a caller could read a message from a channel they cannot access by passing its id as the thread root. Require the parent to be in the requested channel before returning it, and reject a posted parent_id/reply_to_id that does not belong to the channel.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Replace per-message database queries with batch IN-clause queries in
channel message handlers. This eliminates the N+1 query pattern that
caused ~102 queries per channel page load (50 messages × 2 queries each).
Changes:
- Add get_reactions_by_message_ids() to MessageTable: single query
fetches all reactions for multiple messages using IN clause with
User JOIN, returns dict[message_id, list[Reactions]]
- Add get_thread_reply_counts_by_message_ids() to MessageTable: single
GROUP BY aggregate query returns (count, max_created_at) per parent,
replacing full object loads just to call len()
- Refactor get_channel_messages(): 102 → 4 queries per page
- Refactor get_pinned_channel_messages(): 22 → 3 queries per page
- Refactor get_channel_thread_messages(): 53 → 4 queries per page
- Refactor send_notification(): N+1 membership check → batch set lookup
