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>

apps/desktop/src-tauri/Cargo.toml

@@ -29,6 +29,8 @@ serde_json = "1"
 sysinfo = { version = "0.31", default-features = false, features = ["multithread", "network", "system", "disk"] }
 get_if_addrs = "0.5"
 reqwest = { version = "0.12", features = ["json", "rustls-tls", "blocking"], default-features = false }
+reqwest-eventsource = "0.6"
+futures-util = "0.3"
 tokio = { version = "1", features = ["rt-multi-thread", "macros", "time"] }
 once_cell = "1.19"
 thiserror = "1.0"