fix: 调整相似度阈值以优化知识库检索逻辑

- 将多个地方的相似度阈值从0.5降低至0.45，以提高知识库结果的相关性匹配
- 更新相关数据库文件和二进制数据，确保数据一致性

th_agenter/api/endpoints/agent_chat.py

@@ -89,7 +89,7 @@ async def agent_chat(
         results = all_results[: body.top_k]
         max_score = _score(results[0]) if results else 0.0
 
-        if results and max_score >= 0.5:
+        if results and max_score >= 0.45:
             knowledge_base_used = True
             first_kb_id_used = kb_ids[0]
             refs = []
@@ -243,7 +243,7 @@ async def agent_chat_stream(
         results = all_results[: body.top_k]
         max_score = _score(results[0]) if results else 0.0
 
-        if results and max_score >= 0.5:
+        if results and max_score >= 0.45:
             knowledge_base_used = True
             refs = []
             for i, r in enumerate(results[:5], 1):

th_agenter/services/workflow_engine.py

@@ -730,7 +730,7 @@ class WorkflowEngine:
                     if score > max_score:
                         max_score = score
 
-                is_relevant = max_score >= 0.5
+                is_relevant = max_score >= 0.45
 
                 if is_relevant:
                     # 有相关的知识库结果，构建 RAG 风格的提示词
@@ -1310,7 +1310,7 @@ class WorkflowEngine:
         
         query = config.get('query', '')
         top_k = config.get('top_k', config.get('topK', 5))
-        similarity_threshold = config.get('similarity_threshold', config.get('similarityThreshold', 0.7))
+        similarity_threshold = config.get('similarity_threshold', config.get('similarityThreshold', 0.45))
         
         # 如果还是没有，尝试从节点名称中提取（例如 "knowledge-base 2" -> 2）
         if not knowledge_base_id: