fix(server): thread request ctx through session bootstrap, drop Background DB calls

- getOrCreateSession now takes ctx; GetSessionOwnerID/
  RestoreSessionContext/CompilePromptGuidance run under
  context.WithTimeout(5s) instead of context.Background()
- SyncRecentDialogue's rolling summary uses a 30s timeout context
  instead of Background, so client disconnect cancels the LLM call

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

internal/chat/session.go

@@ -176,7 +176,9 @@ func (s *Session) SyncRecentDialogue() {
 
 	// 若发生了截断且存在早期消息，同步计算或加载滚动摘要
 	if truncated && len(early) > 0 && s.CtxMgr != nil {
-		s.syncDialogueSummary(context.Background(), early)
+		ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+		defer cancel()
+		s.syncDialogueSummary(ctx, early)
 	}
 }
 

internal/server/handlers.go

@@ -143,7 +143,7 @@ func (s *Server) handleGetProject(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	sess, err := s.getOrCreateSession(0, sessionID, "", "", "", "", "", "", "", "")
+	sess, err := s.getOrCreateSession(r.Context(), 0, sessionID, "", "", "", "", "", "", "", "")
 	if err != nil || sess == nil || sess.UserCtx == nil {
 		writeSafeError(w, r, http.StatusNotFound, "session or project context not found")
 		return
@@ -170,6 +170,7 @@ func (s *Server) handleChat(w http.ResponseWriter, r *http.Request) {
 	req.WorkDir = ""
 
 	sess, err := s.getOrCreateSession(
+		r.Context(),
 		user.ID,
 		req.SessionID,
 		req.ProjectName,

internal/server/server.go

@@ -403,6 +403,7 @@ func (s *Server) cleanStaleSessionsLocked(ttl time.Duration) int {
 
 // getOrCreateSession 获取或动态构建会话。callerUserID>0 时校验持久层归属，不匹配返回 ErrSessionOwnerMismatch。
 func (s *Server) getOrCreateSession(
+	ctx context.Context,
 	callerUserID int64,
 	sessionID string,
 	projectName string,
@@ -420,7 +421,10 @@ func (s *Server) getOrCreateSession(
 
 	// 归属校验必须先于任何缓存命中/持久层灌入
 	if callerUserID > 0 && s.ctxMgr != nil {
-		if owner, err := s.ctxMgr.GetSessionOwnerID(context.Background(), sessionID); err == nil && owner > 0 && owner != callerUserID {
+		dbCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
+		owner, err := s.ctxMgr.GetSessionOwnerID(dbCtx, sessionID)
+		cancel()
+		if err == nil && owner > 0 && owner != callerUserID {
 			return nil, ctxmgr.ErrSessionOwnerMismatch
 		}
 	}
@@ -455,7 +459,10 @@ func (s *Server) getOrCreateSession(
 	// 尝试从持久层恢复会话上下文 (服务重启后跨进程保持 G3)
 	var restored *ctxmgr.RestoredSessionContext
 	if s.ctxMgr != nil {
-		if r, err := s.ctxMgr.RestoreSessionContext(context.Background(), sessionID); err == nil && r != nil && len(r.Messages) > 0 {
+		dbCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
+		r, err := s.ctxMgr.RestoreSessionContext(dbCtx, sessionID)
+		cancel()
+		if err == nil && r != nil && len(r.Messages) > 0 {
 			restored = r
 		}
 	}
@@ -563,7 +570,10 @@ func (s *Server) getOrCreateSession(
 		}
 
 		if sess.UserID > 0 && sess.CtxMgr != nil {
-			if guidance, err := sess.CtxMgr.CompilePromptGuidance(context.Background(), sess.UserID); err == nil && guidance != "" {
+			dbCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
+			guidance, err := sess.CtxMgr.CompilePromptGuidance(dbCtx, sess.UserID)
+			cancel()
+			if err == nil && guidance != "" {
 				_ = coordinator.ApplyContextUpdate(userCtx, coordinator.ContextUpdate{
 					ExpectedVersion:         userCtx.Version,
 					SetPersonalizedGuidance: true,

internal/server/sse.go

@@ -174,6 +174,7 @@ func (s *Server) handleChatStream(w http.ResponseWriter, r *http.Request) {
 
 	// 会话与项目绑定必须在 SSE headers/Flush 之前完成授权（与 tasks/run/stream 对齐）
 	sess, err := s.getOrCreateSession(
+		r.Context(),
 		user.ID,
 		req.SessionID,
 		req.ProjectName,