Hey - I've left some high level feedback:

• The inline chatsRaw type is starting to diverge from other chat upsert logic (e.g. the handler that already maps unreadMessages); consider extracting a shared type/interface for these raw chat objects so future changes (like adding fields) stay in sync across the different insert/update paths.
• By forcing unreadMessages: chat.unreadCount ?? 0 you override any DB-level default; if the intent is to distinguish between "server explicitly said 0" and "no unread count provided", you might want to pass undefined when chat.unreadCount is undefined and let the existing schema/defaults handle that case.

Please address the comments from this code review:

## Overall Comments
- The inline `chatsRaw` type is starting to diverge from other chat upsert logic (e.g. the handler that already maps `unreadMessages`); consider extracting a shared type/interface for these raw chat objects so future changes (like adding fields) stay in sync across the different insert/update paths.
- By forcing `unreadMessages: chat.unreadCount ?? 0` you override any DB-level default; if the intent is to distinguish between "server explicitly said 0" and "no unread count provided", you might want to pass `undefined` when `chat.unreadCount` is `undefined` and let the existing schema/defaults handle that case.

Approved.

Reviewed independently against develop:

• Real bug confirmed: in messaging-history.set the assembled chat object never included unreadMessages, so the createMany insert always fell back to the column default 0 — every history-synced chat lost its unread count. Adding unreadMessages: chat.unreadCount fixes it, and the JSON.parse(JSON.stringify(...)) round-trip drops the key when the value is undefined, so the column default still applies in that case (identical to before) while the real value is preserved when present.
• I also checked the change on the chats.upsert path (chat.unreadCount !== undefined ? ... : 0 → chat.unreadCount): the chatsToInsert object is shared between the webhook and the DB createMany. When unreadCount is undefined, Prisma omits it and the column default 0 still applies, so the DB outcome is unchanged. Every internal consumer of unreadMessages (the SQL reads in channel.service and updateChatUnreadMessages) reads from the DB column, never from the webhook payload — so there is no internal dependency on the payload carrying 0. The only observable difference is that external webhook consumers receive the key omitted instead of 0 when no count is reported, which the PR documents as intentional. No regression.
• ChatRaw is coherent (no name collision; compiles cleanly under strict:false).

LGTM 👍

Non-blocking suggestion for a follow-up commit (not required to merge): ChatRaw could declare the baileys-nullable fields more precisely as name?: string | null and unreadMessages?: number | null (baileys' IConversation.name/unreadCount are string|null/number|null). Harmless under the current strict:false config — just a typing-precision nit you could fold in next time.