fix: 压制 agentMessage lifecycle 噪声 (#72)

Co-authored-by: Codex <codex@pikas.tech>

docs/reference/spec-v01-backend-adapter.md

@@ -38,7 +38,7 @@ Backend adapter 的第一阶段实现应吸收 HWLAB v0.2 已验证的 Codex std
 | --- | --- | --- |
 | Codex app-server JSON-RPC stdio | `internal/cloud/codex-stdio-session.ts`、`internal/cloud/codex-stdio-session-turn-state.ts` | 支持 `initialize`、`thread/start`、`thread/resume`、`turn/start`，并处理 app-server client request；未知请求要记录 unsupported error，不能静默等待。 |
 | completed 判定 | `docs/reference/code-agent-chat-readiness.md` | 只有 Codex turn terminal completed 且 assistant reply 可聚合时才输出 completed；assistant delta、item completed、stdout 或 transport close 不能单独完成。 |
-| assistant stream 和 trace | `internal/cloud/code-agent-trace-store.ts`、`internal/cloud/codex-stdio-session-turn-state.ts` | assistant delta 只能作为 stream/progress 证据；每个非空 completed `agentMessage` item 必须输出一个 `assistant_message` event，保留 `itemId` 和顺序；最终 result reply 必须优先来自最后一个 completed `agentMessage` item，不能把 commentary/progress delta 与 final response 直接串接。event 必须保留 `threadId`、`turnId`、session 摘要和 redacted backend metadata。 |
+| assistant stream 和 trace | `internal/cloud/code-agent-trace-store.ts`、`internal/cloud/codex-stdio-session-turn-state.ts` | assistant delta 只能作为 stream/progress 证据；每个非空 completed `agentMessage` item 必须输出一个 `assistant_message` event，保留 `itemId` 和顺序；`item/agentMessage:started`、`item/agentMessage:completed` 这类 lifecycle 不得额外持久化为 `backend_status`，避免同一消息在 Web/CLI trace 中重复渲染；最终 result reply 必须优先来自最后一个 completed `agentMessage` item，不能把 commentary/progress delta 与 final response 直接串接。event 必须保留 `threadId`、`turnId`、session 摘要和 redacted backend metadata。 |
 | command/tool output bounded | `docs/reference/code-agent-chat-readiness.md`、`web/hwlab-cloud-web/app-trace.ts` | `tool_call` 和 `command_output` 必须记录状态、摘要、字节数、截断标记；完整大输出只能通过后续 log/artifact 引用。 |
 | provider/profile 隔离 | `internal/cloud/code-agent-contract.ts` | `codex`、`deepseek` 与 `minimax-m3` 共享同一 backend kind，但必须使用 profile-scoped SecretRef、model/base-url/config 和 writable runtime home。 |
 | Secret redaction | `internal/cloud/code-agent-trace-store.ts` | `OPENAI_API_KEY`、auth/config、token、password、kubeconfig、URL credential 不得进入 event、result、log 或 health。 |

src/backend/codex-stdio.ts

@@ -600,7 +600,7 @@ function normalizeCodexNotification(message: JsonRecord, suppressed: SuppressedN
     const text = method === "item/completed" ? agentMessageText(item) : "";
     const completedAssistantMessage = text.trim().length > 0 ? { itemId: itemId ?? null, text } : undefined;
     return {
-      events: [{ type: "backend_status", payload: { phase: method === "item/completed" ? "item/agentMessage:completed" : "item/agentMessage:started", itemId, textBytes: Buffer.byteLength(text, "utf8") } }],
+      events: [],
       ...(completedAssistantMessage ? { completedAssistantMessage } : {}),
     };
   }

src/selftest/cases/30-codex-stdio.ts

@@ -92,6 +92,7 @@ const selfTest: SelfTestCase = async (context) => {
     const turnCompletedIndex = finalMessageItems.findIndex((event) => event.type === "backend_status" && eventPayload(event).phase === "turn/completed");
     assert.ok(progressMessageIndex >= 0 && progressMessageIndex < turnCompletedIndex, "progress agentMessage should be emitted before turn/completed instead of being delayed to final response");
     assert.ok(finalMessageIndex >= 0 && finalMessageIndex < turnCompletedIndex, "final agentMessage should be emitted before turn/completed instead of being delayed to final response");
+    assert.equal(finalMessageItems.some((event) => event.type === "backend_status" && String(eventPayload(event).phase ?? "").startsWith("item/agentMessage:")), false, "agentMessage lifecycle must not be persisted as backend_status noise");
 
     const staleThread = await createStaleThreadRun(client, context);
     const staleThreadResult = await runOnce({
@@ -144,6 +145,7 @@ const selfTest: SelfTestCase = async (context) => {
     assert.equal(noisyItems.some((event) => event.type === "tool_call" && eventPayload(event).type === "reasoning"), false, "reasoning items must not be persisted as tool_call");
     assert.ok(noisyItems.some((event) => event.type === "tool_call" && eventPayload(event).method === "item/started" && eventPayload(event).type === "commandExecution"), "real commandExecution tool call should remain visible");
     assert.equal(noisyItems.some((event) => event.type === "tool_call" && eventPayload(event).type !== "commandExecution"), false, "non-commandExecution item lifecycle must not be persisted as tool_call");
+    assert.equal(noisyItems.some((event) => event.type === "backend_status" && String(eventPayload(event).phase ?? "").startsWith("item/agentMessage:")), false, "agentMessage lifecycle must not be persisted as backend_status noise");
     assert.equal(noisyPhases.includes("backend-turn-running"), false, "backend progress ticks must be summarized instead of persisted as durable trace events");
     const noisyFinished = noisyItems.find((event) => event.type === "backend_status" && eventPayload(event).phase === "backend-turn-finished");
     assert.equal(eventPayload(noisyFinished ?? { payload: {} }).progressEventsPrinted, false, "backend-turn-finished must declare progress ticks were not printed as events");