diff --git a/conversation-repair.mjs b/conversation-repair.mjs
index 0f62f1f..a827496 100644
--- a/conversation-repair.mjs
+++ b/conversation-repair.mjs
@@ -4,6 +4,7 @@
  */
 
 import { extractConversationMessageText } from './conversation-memory.mjs';
+import { mergeConversationSnapshot } from './chat-finish-sync.mjs';
 
 export function parseStoredConversationRow(row) {
   if (!row) return null;
@@ -215,6 +216,15 @@ export function repairConversationFromDbRows(gooseMessages, dbRows) {
     return Array.isArray(gooseMessages) ? gooseMessages : [];
   }
   if (dbBuilt.length === 0) return Array.isArray(gooseMessages) ? gooseMessages : [];
+  const goose = Array.isArray(gooseMessages) ? gooseMessages : [];
+  const dbIds = new Set(dbBuilt.map((message) => message?.id).filter(Boolean));
+  const hasSharedAnchor = goose.some((message) => message?.id && dbIds.has(message.id));
+  if (hasSharedAnchor) {
+    // A recovered Goose session can contain only the last DB-backed user turn
+    // plus replies created after rotation. Prefer DB content for shared history,
+    // while retaining every Goose-only reply and follow-up around that anchor.
+    return mergeConversationSnapshot(goose, dbBuilt);
+  }
   return dbBuilt;
 }
 
diff --git a/conversation-repair.test.mjs b/conversation-repair.test.mjs
index a4b1070..5aecb08 100644
--- a/conversation-repair.test.mjs
+++ b/conversation-repair.test.mjs
@@ -69,6 +69,70 @@ test('shouldRepairConversationFromDb when goose has empty placeholders', () => {
   assert.match(repaired[1].content[0].text, /中考/);
 });
 
+test('repairConversationFromDbRows retains the fresh Goose tail after session recovery', () => {
+  const goose = [
+    gooseMsg('recovery-user', 'user', '【Memind 任务编排】继续修改页面'),
+    gooseMsg('fresh-assistant', 'assistant', '第一轮修改已完成'),
+    gooseMsg('followup-user', 'user', '再加一个页脚'),
+    gooseMsg('followup-assistant', 'assistant', '页脚也已完成'),
+  ];
+  const dbRows = [
+    {
+      message_key: 'old-user',
+      role: 'user',
+      text: '写一首诗并做成页面',
+      created_at: 1,
+      sequence_no: 0,
+    },
+    {
+      message_key: 'old-assistant',
+      role: 'assistant',
+      text: '初版页面已完成',
+      created_at: 2,
+      sequence_no: 1,
+    },
+    {
+      message_key: 'old-followup-user',
+      role: 'user',
+      text: '把标题改成金色',
+      created_at: 3,
+      sequence_no: 2,
+    },
+    {
+      message_key: 'old-followup-assistant',
+      role: 'assistant',
+      text: '标题已改成金色',
+      created_at: 4,
+      sequence_no: 3,
+    },
+    {
+      message_key: 'recovery-user',
+      role: 'user',
+      text: '继续修改页面',
+      created_at: 5,
+      sequence_no: 4,
+    },
+  ];
+
+  const repaired = repairConversationFromDbRows(goose, dbRows);
+
+  assert.deepEqual(
+    repaired.map((message) => message.id),
+    [
+      'old-user',
+      'old-assistant',
+      'old-followup-user',
+      'old-followup-assistant',
+      'recovery-user',
+      'fresh-assistant',
+      'followup-user',
+      'followup-assistant',
+    ],
+  );
+  assert.equal(repaired[4].content[0].text, '继续修改页面');
+  assert.equal(repaired[7].content[0].text, '页脚也已完成');
+});
+
 test('shouldRepairConversationFromDb returns false when goose is complete', () => {
   const goose = [
     gooseMsg('u1', 'user', 'hello'),
diff --git a/docs/regression-guards/mindspace-publish-and-chat-finish.md b/docs/regression-guards/mindspace-publish-and-chat-finish.md
index 1dde04c..82066c3 100644
--- a/docs/regression-guards/mindspace-publish-and-chat-finish.md
+++ b/docs/regression-guards/mindspace-publish-and-chat-finish.md
@@ -211,6 +211,19 @@ runtime 也必须和发布 manifest 的 git commit 对齐。
 - 源码静态检查：`npm run verify:chat-finish-sync`
 - 文档：本文件
 
+### 恢复会话快照：禁止用旧 DB 历史覆盖新回复
+
+视觉上下文不兼容等故障会把 Agent Run 旋转到新 Goose session。新 session
+可能只包含最后一条数据库已同步的用户消息，以及旋转后新生成的助手回复和后续追问；
+此时数据库旧历史条数通常更多。
+
+- `conversation-repair.mjs` 发现 Goose 与 DB 存在共同消息 ID 时，必须以该 ID
+  为锚点合并：共享历史采用 DB 内容，同时保留 Goose 独有的新回复、后续追问和修改结果
+- 只有双方没有共同消息 ID，且 Goose 确实是空占位/残缺记录时，才允许用 DB 历史整体修复
+- Portal 保存 session snapshot 前不得把“当前同步计数”与“旧 messages_json”组合成伪最新快照
+
+守卫：`conversation-repair.test.mjs` 中的 session recovery fresh-tail 用例。
+
 ---
 
 ## 3. 页面需求澄清：禁止误报“未生成 public HTML”