diff --git a/src/lib/boss-data.ts b/src/lib/boss-data.ts
index cf89e33..1ae1726 100644
--- a/src/lib/boss-data.ts
+++ b/src/lib/boss-data.ts
@@ -2882,8 +2882,6 @@ function appendThreadProgressEventInState(
   return event;
 }
 
-const THREAD_STATUS_FULL_SYNC_INTERVAL_MS = 15 * 60_000;
-
 function normalizeState(raw: Partial<BossState> | undefined): BossState {
   const base = cloneInitialState();
   if (!raw) return syncDerivedState(base);
@@ -7635,6 +7633,15 @@ function shouldQueueProjectUnderstandingSync(
   state: BossState,
   reason: "heartbeat_activity" | "thread_reply" = "heartbeat_activity",
 ) {
+  // 主 Agent 自动向线程发隐藏理解对话当前整体关闭。
+  // 保留现有数据模型，后续如果需要恢复，可在明确产品决策后重新开启。
+  void project;
+  void observedActivityAt;
+  void state;
+  void reason;
+  return false;
+
+  /*
   if (!isDispatchableThreadProject(project)) {
     return false;
   }
@@ -7681,6 +7688,7 @@ function shouldQueueProjectUnderstandingSync(
       task.projectUnderstandingTargetProjectId === project.id &&
       (task.status === "queued" || task.status === "running"),
   );
+  */
 }
 
 function buildProjectUnderstandingSyncPrompt(project: Project, reason: "heartbeat_activity" | "thread_reply") {
diff --git a/src/lib/boss-master-agent.ts b/src/lib/boss-master-agent.ts
index de27af9..5818cc8 100644
--- a/src/lib/boss-master-agent.ts
+++ b/src/lib/boss-master-agent.ts
@@ -1775,35 +1775,6 @@ function buildDeviceImportResolutionPrompt(params: {
   ].join("\n");
 }
 
-function buildDeviceImportUnderstandingPrompt(params: {
-  deviceName: string;
-  draftId: string;
-  candidateId: string;
-  threadDisplayName: string;
-  folderName: string;
-  lastActiveAt: string;
-}) {
-  return [
-    "你正在协助 Boss 控制台完成新设备导入前的项目理解。",
-    "请以当前活跃线程的视角，直接总结这个项目当前最关键的信息。",
-    "输出必须是 JSON，对象结构如下：",
-    '{ "projectGoal": "一句中文目标", "currentProgress": "一句中文进度", "technicalArchitecture": "一句中文架构说明", "currentBlockers": "一句中文阻塞说明", "recommendedNextStep": "一句中文建议动作" }',
-    "要求：",
-    "1. 只输出 JSON，不要输出额外解释。",
-    "2. 用中文，句子短而明确。",
-    "3. 如果某项信息不确定，也要明确写出当前已知范围，不要留空。",
-    "",
-    `deviceName: ${params.deviceName}`,
-    `draftId: ${params.draftId}`,
-    `candidateId: ${params.candidateId}`,
-    `threadDisplayName: ${params.threadDisplayName}`,
-    `folderName: ${params.folderName}`,
-    `lastActiveAt: ${params.lastActiveAt}`,
-    "",
-    "请回答当前项目：目标、进度、技术架构、阻塞点、下一步建议。",
-  ].join("\n");
-}
-
 export async function queueDeviceImportResolutionTask(params: {
   deviceId: string;
   reviewedBy: string;
@@ -1824,35 +1795,7 @@ export async function queueDeviceImportResolutionTask(params: {
   const selectedCandidates = draft.candidates.filter((candidate) =>
     draft.selectedCandidateIds.includes(candidate.candidateId),
   );
-  const understandingTasks = await Promise.all(
-    selectedCandidates
-      .filter((candidate) => candidate.codexThreadRef?.trim())
-      .map((candidate) =>
-        queueMasterAgentTask({
-          projectId: "master-agent",
-          taskType: "conversation_reply",
-          requestMessageId: draft.draftId,
-          requestText: `请总结线程 ${candidate.threadDisplayName} 当前项目目标与进度`,
-          executionPrompt: buildDeviceImportUnderstandingPrompt({
-            deviceName: device.name,
-            draftId: draft.draftId,
-            candidateId: candidate.candidateId,
-            threadDisplayName: candidate.threadDisplayName,
-            folderName: candidate.folderName,
-            lastActiveAt: candidate.lastActiveAt,
-          }),
-          requestedBy: params.reviewedBy,
-          requestedByAccount: params.reviewedBy,
-          deviceId: device.id,
-          deviceImportDraftId: draft.draftId,
-          deviceImportCandidateId: candidate.candidateId,
-          deviceImportCandidateFolderName: candidate.folderName,
-          targetThreadDisplayName: candidate.threadDisplayName,
-          targetCodexThreadRef: candidate.codexThreadRef,
-          targetCodexFolderRef: candidate.codexFolderRef ?? candidate.folderRef,
-        }),
-      ),
-  );
+  const understandingTasks: Array<Awaited<ReturnType<typeof queueMasterAgentTask>>> = [];
   const task = await queueMasterAgentTask({
     projectId: "master-agent",
     taskType: "device_import_resolution",
diff --git a/tests/device-import-draft.test.ts b/tests/device-import-draft.test.ts
index 52e8cc1..1a1aed0 100644
--- a/tests/device-import-draft.test.ts
+++ b/tests/device-import-draft.test.ts
@@ -83,7 +83,7 @@ async function createAuthedRequestFor(
   });
 }
 
-test("device import draft review queues a master-agent task, then completion writes back a ready resolution and apply still works", async () => {
+test("device import draft review queues only the resolution task, then completion writes back a ready resolution and apply still works", async () => {
   await setup();
 
   const enrollmentResponse = await createEnrollmentRoute(
@@ -190,8 +190,7 @@ test("device import draft review queues a master-agent task, then completion wri
   assert.equal(reviewPayload.task.status, "queued");
   assert.equal(reviewPayload.draft?.status, "pending_resolution");
   assert.equal(reviewPayload.resolution, undefined);
-  assert.equal(reviewPayload.understandingTasks?.length, 1);
-  assert.equal(reviewPayload.understandingTasks?.[0]?.status, "queued");
+  assert.equal(reviewPayload.understandingTasks?.length ?? 0, 0);
 
   const reviewedState = await readState();
   const resolutionTask = reviewedState.masterAgentTasks.find(
@@ -207,8 +206,11 @@ test("device import draft review queues a master-agent task, then completion wri
       task.deviceImportDraftId === draftPayload.draft?.draftId &&
       task.status === "queued",
   );
-  assert.ok(understandingTask, "expected import review to leave a queued thread understanding task trace");
-  assert.equal(understandingTask?.targetThreadDisplayName, "北区试产线回归");
+  assert.equal(
+    understandingTask,
+    undefined,
+    "device import review should no longer auto-queue hidden thread sync tasks",
+  );
 
   const completionResponse = await completeMasterTaskRoute(
     await createAuthedRequest(
@@ -237,30 +239,6 @@ test("device import draft review queues a master-agent task, then completion wri
   );
   assert.equal(completionResponse.status, 200);
 
-  const understandingCompletionResponse = await completeMasterTaskRoute(
-    await createAuthedRequest(
-      `http://127.0.0.1:3000/api/v1/master-agent/tasks/${understandingTask?.taskId}/complete`,
-      "POST",
-      {
-        deviceId: enrollmentPayload.device.id,
-        status: "completed",
-        replyBody: JSON.stringify(
-          {
-            projectGoal: "完成北区试产线树莓派二代接入与联调。",
-            currentProgress: "已经完成线程导入准备，当前在核对设备接线和控制链路。",
-            technicalArchitecture: "前台是 Next.js 控制台，设备端通过 local-agent 与 Codex 线程联动。",
-            currentBlockers: "还缺少树莓派二代的串口稳定性验证。",
-            recommendedNextStep: "先确认接线和串口日志，再继续设备控制指令联调。",
-          },
-          null,
-          2,
-        ),
-      },
-    ),
-    { params: Promise.resolve({ taskId: understandingTask?.taskId ?? "" }) },
-  );
-  assert.equal(understandingCompletionResponse.status, 200);
-
   const completedState = await readState();
   const completedDraft = completedState.deviceImportDrafts.find(
     (draft) => draft.deviceId === enrollmentPayload.device.id,
@@ -291,13 +269,8 @@ test("device import draft review queues a master-agent task, then completion wri
     }>;
     understandingTasks?: Array<{ taskId: string; status: string }>;
   };
-  assert.equal(refreshedDraftPayload.projectUnderstandings?.length, 1);
-  assert.equal(refreshedDraftPayload.projectUnderstandings?.[0]?.threadDisplayName, "北区试产线回归");
-  assert.match(
-    refreshedDraftPayload.projectUnderstandings?.[0]?.projectGoal ?? "",
-    /树莓派二代接入与联调/,
-  );
-  assert.equal(refreshedDraftPayload.understandingTasks?.[0]?.status, "completed");
+  assert.equal(refreshedDraftPayload.projectUnderstandings?.length ?? 0, 0);
+  assert.equal(refreshedDraftPayload.understandingTasks?.length ?? 0, 0);
 
   const applyResponse = await applyImportDraftRoute(
     await createAuthedRequest(
@@ -321,23 +294,13 @@ test("device import draft review queues a master-agent task, then completion wri
   assert.ok(importedProject, "expected selected candidate to become a real chat window");
   assert.equal(importedProject?.threadMeta.threadDisplayName, "北区试产线回归");
   assert.equal(importedProject?.threadMeta.folderName, "北区试产线");
-  assert.equal(importedProject?.projectUnderstanding?.projectGoal, "完成北区试产线树莓派二代接入与联调。");
-  assert.match(importedProject?.projectUnderstanding?.technicalArchitecture ?? "", /local-agent 与 Codex 线程联动/);
-  assert.equal(importedProject?.projectUnderstanding?.sourceKind, "device_import");
-  assert.ok(importedProject?.threadMeta.lastProjectUnderstandingSyncedAt);
+  assert.equal(importedProject?.projectUnderstanding, undefined);
+  assert.equal(importedProject?.threadMeta.lastProjectUnderstandingSyncedAt, undefined);
 
   const importedMemories = nextState.masterAgentMemories.filter(
     (memory) => memory.projectId === importedProject?.id,
   );
-  assert.equal(importedMemories.length, 5);
-  assert.equal(
-    importedMemories.find((memory) => memory.title === "项目目标 · 北区试产线回归")?.content,
-    "完成北区试产线树莓派二代接入与联调。",
-  );
-  assert.match(
-    importedMemories.find((memory) => memory.title === "下一步建议 · 北区试产线回归")?.content ?? "",
-    /确认接线和串口日志/,
-  );
+  assert.equal(importedMemories.length, 0);
 
   const device = nextState.devices.find((item) => item.id === enrollmentPayload.device.id);
   assert.deepEqual(device?.projects, ["北区试产线"]);
@@ -394,7 +357,7 @@ test("device import draft review queues a master-agent task, then completion wri
   assert.equal(appliedResolution?.status, "applied");
 });
 
-test("imported thread projects queue hidden understanding sync tasks on newer activity and refresh project understanding", async () => {
+test("imported thread projects append progress events on newer activity without queuing hidden understanding sync tasks", async () => {
   await setup();
 
   const enrollmentResponse = await createEnrollmentRoute(
@@ -493,7 +456,7 @@ test("imported thread projects queue hidden understanding sync tasks on newer ac
       task.deviceImportCandidateId &&
       task.status === "queued",
   );
-  assert.ok(initialUnderstandingTask);
+  assert.equal(initialUnderstandingTask, undefined);
 
   assert.equal(
     (
@@ -524,34 +487,6 @@ test("imported thread projects queue hidden understanding sync tasks on newer ac
     200,
   );
 
-  assert.equal(
-    (
-      await completeMasterTaskRoute(
-        await createAuthedRequest(
-          `http://127.0.0.1:3000/api/v1/master-agent/tasks/${initialUnderstandingTask.taskId}/complete`,
-          "POST",
-          {
-            deviceId: enrollmentPayload.device.id,
-            status: "completed",
-            replyBody: JSON.stringify(
-              {
-                projectGoal: "让智能看板项目能够稳定接入主控面板。",
-                currentProgress: "已经完成导入前梳理，准备开始界面和设备联调。",
-                technicalArchitecture: "Android 原生端连接 Boss Web，再通过 local-agent 对接 Codex 线程。",
-                currentBlockers: "还缺少设备端实时推送状态的统一协议。",
-                recommendedNextStep: "先对齐状态推送协议，再做前后端联调。",
-              },
-              null,
-              2,
-            ),
-          },
-        ),
-        { params: Promise.resolve({ taskId: initialUnderstandingTask.taskId }) },
-      )
-    ).status,
-    200,
-  );
-
   const applyResponse = await applyImportDraftRoute(
     await createAuthedRequest(
       `http://127.0.0.1:3000/api/v1/devices/${enrollmentPayload.device.id}/import-draft/apply`,
@@ -567,7 +502,7 @@ test("imported thread projects queue hidden understanding sync tasks on newer ac
     (project) => project.threadMeta.codexThreadRef === "thread-smart-board",
   );
   assert.ok(importedProject);
-  assert.equal(importedProject?.projectUnderstanding?.currentProgress, "已经完成导入前梳理，准备开始界面和设备联调。");
+  assert.equal(importedProject?.projectUnderstanding, undefined);
   const progressEventsBefore = currentState.threadProgressEvents.filter(
     (event) => event.projectId === importedProject?.id,
   ).length;
@@ -599,7 +534,7 @@ test("imported thread projects queue hidden understanding sync tasks on newer ac
       task.projectUnderstandingReason === "heartbeat_activity" &&
       task.status === "queued",
   );
-  assert.ok(hiddenSyncTask);
+  assert.equal(hiddenSyncTask, undefined);
 
   const progressEventsAfter = currentState.threadProgressEvents.filter(
     (event) => event.projectId === importedProject?.id,
@@ -608,41 +543,11 @@ test("imported thread projects queue hidden understanding sync tasks on newer ac
   assert.equal(progressEventsAfter[0]?.eventType, "progress_updated");
   assert.match(progressEventsAfter[0]?.summary ?? "", /北区试产线回归|新活动/);
 
-  assert.equal(
-    (
-      await completeMasterTaskRoute(
-        await createAuthedRequest(
-          `http://127.0.0.1:3000/api/v1/master-agent/tasks/${hiddenSyncTask.taskId}/complete`,
-          "POST",
-          {
-            deviceId: enrollmentPayload.device.id,
-            status: "completed",
-            replyBody: JSON.stringify(
-              {
-                projectGoal: "让智能看板项目能够稳定接入主控面板。",
-                currentProgress: "已完成状态推送协议对齐，正在推进前后端联调。",
-                technicalArchitecture: "Android 原生端连接 Boss Web，再通过 local-agent 对接 Codex 线程。",
-                currentBlockers: "还缺少最终的真机联调回归。",
-                recommendedNextStep: "先完成真机联调，再收口回归问题。",
-              },
-              null,
-              2,
-            ),
-          },
-        ),
-        { params: Promise.resolve({ taskId: hiddenSyncTask.taskId }) },
-      )
-    ).status,
-    200,
-  );
-
   currentState = await readState();
 
   const refreshedProject = currentState.projects.find((project) => project.id === importedProject?.id);
-  assert.equal(refreshedProject?.projectUnderstanding?.currentProgress, "已完成状态推送协议对齐，正在推进前后端联调。");
-  assert.match(refreshedProject?.projectUnderstanding?.technicalArchitecture ?? "", /Android 原生端连接 Boss Web/);
-  assert.equal(refreshedProject?.projectUnderstanding?.sourceKind, "thread_sync");
-  assert.ok(refreshedProject?.threadMeta.lastProjectUnderstandingSyncedAt);
+  assert.equal(refreshedProject?.projectUnderstanding, undefined);
+  assert.equal(refreshedProject?.threadMeta.lastProjectUnderstandingSyncedAt, undefined);
 
   assert.equal(
     currentState.masterAgentMemories.find(
@@ -650,7 +555,7 @@ test("imported thread projects queue hidden understanding sync tasks on newer ac
         memory.projectId === refreshedProject?.id &&
         memory.title === "项目进度 · 智能看板主线程",
     )?.content,
-    "已完成状态推送协议对齐，正在推进前后端联调。",
+    undefined,
   );
   assert.equal(
     currentState.masterAgentMemories.find(
@@ -658,16 +563,14 @@ test("imported thread projects queue hidden understanding sync tasks on newer ac
         memory.projectId === refreshedProject?.id &&
         memory.title === "下一步建议 · 智能看板主线程",
     )?.content,
-    "先完成真机联调，再收口回归问题。",
+    undefined,
   );
 
   const masterAgentProject = currentState.projects.find((project) => project.id === "master-agent");
   const collaborationNotice = (masterAgentProject?.messages ?? [])
     .map((message) => message.body)
     .find((body) => body.includes("协同推进"));
-  assert.match(collaborationNotice ?? "", /主 Agent 已同步：智能看板主线程/);
-  assert.match(collaborationNotice ?? "", /不会中断你继续直接控制线程开发/);
-  assert.ok(!(collaborationNotice ?? "").includes("可接手"));
+  assert.equal(collaborationNotice, undefined);
 });
 
 test("heartbeat candidates no longer auto-create chat windows from legacy projects when import draft is present", async () => {