feat(workflow): augment logging queries and ameliorate error handling

- Augment log search with app type filtering to enable keyword searching within workflow_executions.
- Introduce execution sequence markers to ensure logs are displayed in the correct chronological order.
- Ameliorate error handling to capture successful node outputs alongside failure details.
- Rectify the processing of empty JSON bodies in HTTP request nodes.

api/app/repositories/conversation_repository.py

@@ -1,13 +1,15 @@
 import uuid
 from typing import Optional
 
-from sqlalchemy import select, desc, func
+from sqlalchemy import select, desc, func, or_, cast, Text
 from sqlalchemy.orm import Session
 
 from app.core.exceptions import ResourceNotFoundException
 from app.core.logging_config import get_db_logger
 from app.models import Conversation, Message
+from app.models.app_model import AppType
 from app.models.conversation_model import ConversationDetail
+from app.models.workflow_model import WorkflowExecution
 
 logger = get_db_logger()
 
@@ -206,7 +208,8 @@ class ConversationRepository:
             is_draft: Optional[bool] = None,
             keyword: Optional[str] = None,
             page: int = 1,
-            pagesize: int = 20
+            pagesize: int = 20,
+            app_type: Optional[str] = None,
     ) -> tuple[list[Conversation], int]:
         """
         查询应用日志会话列表（带分页和过滤）
@@ -218,6 +221,9 @@ class ConversationRepository:
             keyword: 搜索关键词（匹配消息内容）
             page: 页码（从 1 开始）
             pagesize: 每页数量
+            app_type: 应用类型。WORKFLOW 类型改用 workflow_executions 的
+                input_data/output_data 做关键词过滤（因为失败的工作流不会写入 messages 表）；
+                其他类型仍走 messages 表。
 
         Returns:
             Tuple[List[Conversation], int]: (会话列表，总数)
@@ -234,12 +240,28 @@ class ConversationRepository:
 
         # 如果有关键词搜索，通过子查询过滤包含该关键词的 conversation
         if keyword:
-            # 查找包含关键词的 conversation_id 列表
-            keyword_stmt = (
-                select(Message.conversation_id)
-                .where(Message.content.ilike(f"%{keyword}%"))
-                .distinct()
-            )
+            kw_pattern = f"%{keyword}%"
+            if app_type == AppType.WORKFLOW:
+                # 工作流：从 workflow_executions 的 input_data / output_data 匹配
+                # （messages 表只存开场白 assistant 消息，失败的工作流也不会写入）
+                keyword_stmt = (
+                    select(WorkflowExecution.conversation_id)
+                    .where(
+                        WorkflowExecution.conversation_id.is_not(None),
+                        or_(
+                            cast(WorkflowExecution.input_data, Text).ilike(kw_pattern),
+                            cast(WorkflowExecution.output_data, Text).ilike(kw_pattern),
+                        ),
+                    )
+                    .distinct()
+                )
+            else:
+                # Agent 等其他类型：仍走 messages 表（user + assistant 内容)
+                keyword_stmt = (
+                    select(Message.conversation_id)
+                    .where(Message.content.ilike(kw_pattern))
+                    .distinct()
+                )
             base_stmt = base_stmt.where(Conversation.id.in_(keyword_stmt))
 
         # Calculate total number of records