feat: SSE para chat desktop, rate limiting, retry, testes e atualizacao de stack

- Implementa Server-Sent Events (SSE) para chat no desktop com fallback HTTP
- Adiciona rate limiting nas APIs de chat (poll, messages, sessions)
- Adiciona retry com backoff exponencial para mutations
- Cria testes para modulo liveChat (20 testes)
- Corrige testes de SMTP (unit tests para extractEnvelopeAddress)
- Adiciona indice by_status_lastActivity para cron de sessoes inativas
- Atualiza stack: Bun 1.3.4, React 19, recharts 3, noble/hashes 2, etc

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

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

convex/liveChat.ts

@@ -3,8 +3,8 @@ import { action, mutation, query, type MutationCtx, type QueryCtx } from "./_gen
 import { ConvexError } from "convex/values"
 import { api } from "./_generated/api"
 import type { Doc, Id } from "./_generated/dataModel"
-import { sha256 } from "@noble/hashes/sha256"
-import { bytesToHex as toHex } from "@noble/hashes/utils"
+import { sha256 } from "@noble/hashes/sha2.js"
+import { bytesToHex as toHex } from "@noble/hashes/utils.js"
 
 // ============================================
 // HELPERS
@@ -728,14 +728,11 @@ export const autoEndInactiveSessions = mutation({
     // Limitar a 50 sessões por execução para evitar timeout do cron (30s)
     const maxSessionsPerRun = 50
 
-    // Buscar sessões ativas com inatividade > 5 minutos (com limite)
+    // Buscar sessões ativas com inatividade > 5 minutos (usando índice otimizado)
     const inactiveSessions = await ctx.db
       .query("liveChatSessions")
-      .filter((q) =>
-        q.and(
-          q.eq(q.field("status"), "ACTIVE"),
-          q.lt(q.field("lastActivityAt"), cutoffTime)
-        )
+      .withIndex("by_status_lastActivity", (q) =>
+        q.eq("status", "ACTIVE").lt("lastActivityAt", cutoffTime)
       )
       .take(maxSessionsPerRun)