fix(chat): melhora confiabilidade da deteccao de novas mensagens

- Implementa deteccao dual: timestamp (lastActivityAt) + contador
- Adiciona persistencia de estado em ~/.local/share/Raven/chat-state.json
- Corrige race condition no servidor com refetch antes do patch
- Adiciona campo lastAgentMessageAt no schema do Convex
- Adiciona logs de diagnostico detalhados

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

convex/schema.ts

@@ -478,6 +478,7 @@ export default defineSchema({
     startedAt: v.number(),
     endedAt: v.optional(v.number()),
     lastActivityAt: v.number(),
+    lastAgentMessageAt: v.optional(v.number()), // Timestamp da ultima mensagem do agente (para deteccao confiavel)
     unreadByMachine: v.optional(v.number()),
     unreadByAgent: v.optional(v.number()),
   })

convex/tickets.ts

@@ -3734,6 +3734,8 @@ export const postChatMessage = mutation({
     await ctx.db.patch(ticketId, { updatedAt: now })
 
     // Se o autor for um agente (ADMIN, MANAGER, AGENT), incrementar unreadByMachine na sessao de chat ativa
+    // IMPORTANTE: Buscar sessao IMEDIATAMENTE antes do patch para evitar race conditions
+    // O Convex faz retry automatico em caso de OCC conflict
     const actorRole = participant.role?.toUpperCase() ?? ""
     if (["ADMIN", "MANAGER", "AGENT"].includes(actorRole)) {
       const activeSession = await ctx.db
@@ -3743,10 +3745,15 @@ export const postChatMessage = mutation({
         .first()
 
       if (activeSession) {
-        await ctx.db.patch(activeSession._id, {
-          unreadByMachine: (activeSession.unreadByMachine ?? 0) + 1,
-          lastActivityAt: now,
-        })
+        // Refetch para garantir valor mais recente (OCC protection)
+        const freshSession = await ctx.db.get(activeSession._id)
+        if (freshSession) {
+          await ctx.db.patch(activeSession._id, {
+            unreadByMachine: (freshSession.unreadByMachine ?? 0) + 1,
+            lastActivityAt: now,
+            lastAgentMessageAt: now, // Novo: timestamp da ultima mensagem do agente
+          })
+        }
       }
     }