feat(memory): add session-based chat history and user metadata retrieval

- Add ChatSessionCache to manage chat history per session
- Add SEARCH_USER_METADATA cypher query for retrieving user entity metadata
- Add "str" mode support to StructResponse for raw text extraction
- Add content_str field to MemorySearchResult for pre-formatted content
- Fix sandbox URL by removing hardcoded port
- Add description field to entity search results
- Remove history from UserInput schema, use session_id instead

api/app/repositories/neo4j/cypher_queries.py

@@ -1296,6 +1296,7 @@ RETURN e.id AS id,
        e.name AS name,
        e.end_user_id AS end_user_id,
        e.entity_type AS entity_type,
+       e.description AS description,
        COALESCE(e.activation_value, e.importance_score, 0.5) AS activation_value,
        COALESCE(e.importance_score, 0.5) AS importance_score,
        e.last_access_time AS last_access_time,
@@ -1479,6 +1480,21 @@ ORDER BY score DESC
 LIMIT $limit
 """
 
+SEARCH_USER_METADATA = """
+MATCH (n:ExtractedEntity)
+WHERE (n.end_user_id = $end_user_id AND n.entity_type ='用户')
+RETURN n.description AS description,
+       n.aliases AS aliases,
+       n.anchors AS anchors,
+       n.beliefs_or_stances AS beliefs_or_stances,
+       n.core_facts AS core_facts,
+       n.events AS events,
+       n.goals AS goals,
+       n.interests AS interests,
+       n.relations AS relations,
+       n.traits AS traits
+"""
+
 FULLTEXT_QUERY_CYPHER_MAPPING = {
     Neo4jNodeType.STATEMENT: SEARCH_STATEMENTS_BY_KEYWORD,
     Neo4jNodeType.EXTRACTEDENTITY: SEARCH_ENTITIES_BY_NAME_OR_ALIAS,

api/app/repositories/neo4j/graph_search.py

@@ -27,9 +27,9 @@ from app.repositories.neo4j.cypher_queries import (
     SEARCH_PERCEPTUAL_BY_USER_ID,
     FULLTEXT_QUERY_CYPHER_MAPPING,
     USER_ID_QUERY_CYPHER_MAPPING,
-    NODE_ID_QUERY_CYPHER_MAPPING
+    NODE_ID_QUERY_CYPHER_MAPPING,
+    SEARCH_USER_METADATA
 )
-
 from app.repositories.neo4j.neo4j_connector import Neo4jConnector
 
 logger = logging.getLogger(__name__)
@@ -513,7 +513,7 @@ async def search_graph_by_embedding(
     task_keys = []
 
     for node_type in include:
-        tasks.append(search_by_embedding(connector, node_type, end_user_id, embedding, limit*2))
+        tasks.append(search_by_embedding(connector, node_type, end_user_id, embedding, limit * 2))
         task_keys.append(node_type.value)
 
     task_results = await asyncio.gather(*tasks, return_exceptions=True)
@@ -557,6 +557,17 @@ async def search_graph_by_embedding(
     return results
 
 
+async def search_user_metadata(
+        connector: Neo4jConnector,
+        end_user_id: str
+) -> dict:
+    user_info = await connector.execute_query(
+        SEARCH_USER_METADATA,
+        end_user_id=end_user_id
+    )
+    return user_info[0] if user_info else {}
+
+
 async def get_dedup_candidates_for_entities(  # 适配新版查询：使用全文索引按名称检索候选实体
         connector: Neo4jConnector,
         end_user_id: str,