fix(ctxmgr): 补齐 rows.Err() 检查（R-2，ctxmgr 包）

A 类硬失败返回；manager 降级读路径用 slog.Warn 保持既有容忍语义。

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

internal/ctxmgr/case_indexing.go

@@ -196,7 +196,7 @@ func (m *ContextManager) SearchSimilarCases(ctx context.Context, opts CaseSearch
 				results = append(results, item)
 			}
 		}
-		return results, nil
+		return results, rows.Err()
 	}
 
 	m.mu.RLock()

internal/ctxmgr/chat_digest.go

@@ -50,6 +50,9 @@ func (m *ContextManager) GenerateDailyDigest(ctx context.Context, sessionID, day
 			rec.CreatedAt = createdAt
 			msgs = append(msgs, rec)
 		}
+		if err := rows.Err(); err != nil {
+			return nil, fmt.Errorf("scan digest messages failed: %w", err)
+		}
 	} else {
 		m.mu.RLock()
 		for _, r := range m.messages[sessionID] {
@@ -367,6 +370,9 @@ func (m *ContextManager) ListDailyDigests(ctx context.Context, sessionID, from,
 		_ = json.Unmarshal(oqBytes, &d.OpenQuestions)
 		digests = append(digests, d)
 	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("scan digests failed: %w", err)
+	}
 
 	return digests, nil
 }

internal/ctxmgr/chat_history.go

@@ -152,7 +152,7 @@ func (m *ContextManager) ListChatSessions(ctx context.Context, filter SessionFil
 				sessions = append(sessions, item)
 			}
 		}
-		return sessions, nil
+		return sessions, rows.Err()
 	}
 
 	m.mu.RLock()
@@ -224,7 +224,7 @@ func (m *ContextManager) GetChatHistory(ctx context.Context, sessionID string, l
 				msgs = append(msgs, rec)
 			}
 		}
-		return msgs, nil
+		return msgs, rows.Err()
 	}
 
 	m.mu.RLock()

internal/ctxmgr/chat_memory.go

@@ -285,6 +285,9 @@ func (m *ContextManager) SearchChatMemory(ctx context.Context, opts ChatMemorySe
 				}
 			}
 		}
+		if err := rows.Err(); err != nil {
+			return nil, fmt.Errorf("scan memory chunks failed: %w", err)
+		}
 
 		sort.Slice(candidates, func(i, j int) bool {
 			return candidates[i].FinalScore > candidates[j].FinalScore

internal/ctxmgr/chat_search.go

@@ -101,7 +101,7 @@ func (m *ContextManager) searchChatMessagesKeywordDB(ctx context.Context, q Chat
 			MatchedBy: "keyword",
 		})
 	}
-	return hits, nil
+	return hits, rows.Err()
 }
 
 // searchChatMessagesFuzzyDB 模糊相似度检索 (Postgres pg_trgm similarity)
@@ -160,7 +160,7 @@ func (m *ContextManager) searchChatMessagesFuzzyDB(ctx context.Context, q ChatSe
 			MatchedBy: "fuzzy",
 		})
 	}
-	return hits, nil
+	return hits, rows.Err()
 }
 
 // searchChatMessagesSemanticDB 语义向量检索 (通过 context_memory_chunks 或降级为 keyword)
@@ -232,6 +232,9 @@ func (m *ContextManager) searchChatMessagesSemanticDB(ctx context.Context, q Cha
 			MatchedBy: "semantic",
 		})
 	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("scan semantic search hits failed: %w", err)
+	}
 
 	if len(hits) == 0 {
 		return m.searchChatMessagesKeywordDB(ctx, q)

internal/ctxmgr/chat_unread.go

@@ -322,6 +322,10 @@ func (m *ContextManager) markChatReadPG(ctx context.Context, req MarkChatReadReq
 				futureIDs = append(futureIDs, mid)
 			}
 		}
+		if err := rows.Err(); err != nil {
+			rows.Close()
+			return nil, fmt.Errorf("scan future unread ids failed: %w", err)
+		}
 		rows.Close()
 	}
 

internal/ctxmgr/chat_window.go

@@ -72,6 +72,9 @@ func (m *ContextManager) getChatWindowPG(ctx context.Context, q ChatWindowQuery)
 			descDays = append(descDays, d.Format("2006-01-02"))
 		}
 	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("scan chat window days failed: %w", err)
+	}
 
 	if len(descDays) == 0 {
 		return &ChatWindowResult{
@@ -601,6 +604,9 @@ func (m *ContextManager) ListChatDates(ctx context.Context, sessionID string) ([
 				st.Categories[cat] += cnt
 			}
 		}
+		if err := rows.Err(); err != nil {
+			return nil, fmt.Errorf("scan chat dates failed: %w", err)
+		}
 
 		res := make([]ChatDateStat, 0, len(orderedKeys))
 		for _, k := range orderedKeys {
@@ -688,7 +694,7 @@ func (m *ContextManager) ListChatCategories(ctx context.Context, sessionID strin
 				LastMessageID:  maxID,
 			})
 		}
-		return res, nil
+		return res, rows.Err()
 	}
 
 	m.mu.RLock()

internal/ctxmgr/manager.go

@@ -1,6 +1,7 @@
 package ctxmgr
 
 import (
+	"log/slog"
 	"context"
 	"encoding/json"
 	"errors"
@@ -383,6 +384,9 @@ func (m *ContextManager) GetUserContext(ctx context.Context, projectID, userID i
 						userCtx.RecentChats = append(userCtx.RecentChats, r)
 					}
 				}
+				if err := rows.Err(); err != nil {
+					slog.Warn("ctxmgr_recent_chats_scan_incomplete", "error", err)
+				}
 			}
 		} else {
 			m.mu.RLock()
@@ -410,6 +414,9 @@ func (m *ContextManager) GetUserContext(ctx context.Context, projectID, userID i
 					rawActs = append(rawActs, it)
 				}
 			}
+			if err := rows.Err(); err != nil {
+				slog.Warn("ctxmgr_user_activities_scan_incomplete", "error", err)
+			}
 		}
 	} else {
 		m.mu.RLock()
@@ -481,6 +488,9 @@ func (m *ContextManager) GetProjectContext(ctx context.Context, projectID int64)
 					}
 				}
 			}
+			if err := rows.Err(); err != nil {
+				slog.Warn("ctxmgr_project_activities_scan_incomplete", "error", err)
+			}
 			pCtx.AllActivities = ApplyTimeDecayToActivities(rawActs, m.decayCfg)
 		}
 	} else {
@@ -727,6 +737,9 @@ func (m *ContextManager) ReflectUserPreference(ctx context.Context, userID int64
 					msgs = append(msgs, r)
 				}
 			}
+			if err := rows.Err(); err != nil {
+				slog.Warn("ctxmgr_reflect_msgs_scan_incomplete", "error", err)
+			}
 		}
 	} else {
 		m.mu.RLock()

internal/ctxmgr/project_dialogue.go

@@ -69,6 +69,9 @@ func (m *ContextManager) CollectProjectDialogue(ctx context.Context, projectID i
 			}
 			msgs = append(msgs, rec)
 		}
+		if err := rows.Err(); err != nil {
+			return nil, fmt.Errorf("scan project dialogue failed: %w", err)
+		}
 	} else {
 		m.mu.RLock()
 		for sessionID, sessionMsgs := range m.messages {

internal/ctxmgr/recategorize.go

@@ -64,6 +64,9 @@ func (m *ContextManager) RecategorizeMessages(ctx context.Context, sessionID str
 			}
 			msgs = append(msgs, r)
 		}
+		if err := rows.Err(); err != nil {
+			return nil, fmt.Errorf("scan messages for recategorize failed: %w", err)
+		}
 
 		var lastUserMsg *recatMsg
 		for _, msg := range msgs {