fix: use correct Prisma JSON path filter in getLastMessage (fixes #2495)

The `getLastMessage` function was using an invalid Prisma where-clause
syntax `{ key: { remoteJid: number } }` for a JSON/JSONB field. Prisma
requires `{ key: { path: ['remoteJid'], equals: value } }` to filter on
a JSON field path. This caused a PrismaClientValidationError whenever
`archiveChat` or `markChatUnread` called `getLastMessage` with a chat
number instead of providing lastMessage directly.

Co-Authored-By: Octopus <liyuan851277048@icloud.com>

Author: octo-patch

src/api/integrations/channel/whatsapp/whatsapp.baileys.service.ts

@@ -3689,7 +3689,7 @@ export class BaileysStartupService extends ChannelStartupService {
   }
 
   public async getLastMessage(number: string) {
-    const where: any = { key: { remoteJid: number }, instanceId: this.instance.id };
+    const where: any = { key: { path: ['remoteJid'], equals: number }, instanceId: this.instanceId };
 
     const messages = await this.prismaRepository.message.findMany({
       where,