docs(#08): update A13 revised - exit=0 always completed

Merge old A12/A13 into single A13 revised: trust exit_code=0
regardless of stdout/JSON output. Old logic caused inform Mail
infinite retry loop.

docs/design/08-classify-outcome-optimization.md

@@ -110,8 +110,8 @@ TCP 握手只能检测进程端口是否监听，无法检测 Gateway **业务
 
 | 编号 | 条件 | outcome | 可恢复？ | 处理 |
 |------|------|---------|----------|------|
-| A12 | exit=0 + task_status ∈ {done, review} | completed | — | 正常完成 |
-| A13 | exit=0 + task_status ∉ {done, review} | agent_error | ❌ | 标 failed + 原因写黑板 |
+| A12 | ~~已合并到 A13 revised~~ | — | — | 见下方 A13 revised |
+| **A13 revised** | exit=0（无 JSON 输出） | completed | — | 信任进程退出码，exit=0 即正常完成。旧逻辑按 task_status 区分，非终态判 agent_error → 导致 inform Mail 永不标 done，与 dispatcher inform auto-done 形成死循环 |
 | **A14** | exit=130 (SIGINT) 或 exit=143 (SIGTERM) | interrupted | ✅ | retry |
 | **A15** | exit≠0 + stderr 含 network 关键字 | gateway_unreachable | ✅ | retry + cooldown 30s |
 | **A16** | exit≠0 + stderr 含 compact 关键字 | compact_interrupted | ✅ | retry + cooldown 60s |