fix: repair chat history from DB when Goose session has empty placeholders

Portal direct chat → goosed escalation can leave hollow Goose messages while
h5_conversation_messages retains the full dialogue. Backfill session detail
from DB, extend snapshot list fallback, and keep stored session id on transient
boot failures so refresh no longer looks like a blank new chat.

Co-authored-by: Cursor <cursoragent@cursor.com>

server.mjs

@@ -164,6 +164,7 @@ import { createFeedbackService } from './user-feedback.mjs';
 import { startScheduleReminderWorker } from './schedule-reminder-worker.mjs';
 import { createLlmProviderService, RELAY_BOOTSTRAP } from './llm-providers.mjs';
 import { createDirectChatService, isDirectChatSessionId, isPortalDirectChatSnapshot, sendDirectChatSessionEvents, shouldExpirePortalDirectChatSnapshot } from './direct-chat-service.mjs';
+import { repairSessionConversationFromDb } from './conversation-repair.mjs';
 import { createManagedChatIntentRouter } from './chat-intent-router.mjs';
 import { createSessionSnapshotService } from './session-snapshot.mjs';
 import { createConversationMemoryService } from './conversation-memory.mjs';
@@ -1888,7 +1889,7 @@ async function ensureUserMemoryCapability(req, res) {
   return capabilityState;
 }
 
-async function loadUserVisibleConversation(sessionId) {
+async function loadUserVisibleConversation(sessionId, userId) {
   const target = await tkmindProxy.resolveTarget(sessionId);
   const upstream = await tkmindProxy.apiFetchTo(target, `/sessions/${encodeURIComponent(sessionId)}`, {
     method: 'GET',
@@ -1897,7 +1898,10 @@ async function loadUserVisibleConversation(sessionId) {
     const message = await upstream.text().catch(() => '');
     throw new Error(message || '读取会话失败');
   }
-  const session = await upstream.json();
+  let session = await upstream.json();
+  if (authPool && userId) {
+    session = await repairSessionConversationFromDb(authPool, session, sessionId, userId);
+  }
   return (session?.conversation ?? []).filter((message) => message?.metadata?.userVisible);
 }
 
@@ -1928,7 +1932,7 @@ api.post('/user-memory/v1/remember-recent', async (req, res) => {
   }
 
   try {
-    const messages = await loadUserVisibleConversation(sessionId);
+    const messages = await loadUserVisibleConversation(sessionId, req.currentUser.id);
     const result = await memoryV2.write({
       userId: req.currentUser.id,
       sessionId,
@@ -4469,11 +4473,19 @@ api.get('/sessions/:sessionId', async (req, res, next) => {
             req.currentUser,
           );
           // Cache hit — reconstruct a Goose-compatible session response.
-          const cachedGooseSession = {
+          let cachedGooseSession = {
             ...snapshot.session,
             // Embed only userVisible messages so getSession callers still work.
             conversation: sanitizedMessages,
           };
+          if (authPool) {
+            cachedGooseSession = await repairSessionConversationFromDb(
+              authPool,
+              cachedGooseSession,
+              sessionId,
+              req.currentUser.id,
+            );
+          }
           return res.json(cachedGooseSession);
         }
       }
@@ -4494,13 +4506,21 @@ api.get('/sessions/:sessionId', async (req, res, next) => {
       const text = await upstream.text().catch(() => '');
       return res.status(upstream.status).send(text);
     }
-    const gooseSession = await upstream.json();
+    let gooseSession = await upstream.json();
     if (Array.isArray(gooseSession.conversation)) {
       gooseSession.conversation = sanitizeSessionConversationPublicHtmlLinks(
         gooseSession.conversation,
         req.currentUser,
       );
     }
+    if (authPool) {
+      gooseSession = await repairSessionConversationFromDb(
+        authPool,
+        gooseSession,
+        sessionId,
+        req.currentUser.id,
+      );
+    }
     // Write-through: persist snapshot async, don't block the response.
     if (sessionSnapshotService?.isEnabled()) {
       const messages = (gooseSession.conversation ?? [])