feature:基本框架

config/database/neo4j.py

@@ -0,0 +1,40 @@
+"""Neo4j 会话：全局单例 AsyncDriver（内部自带连接池与事务重试）。"""
+from neo4j import AsyncGraphDatabase
+from config.settings import settings
+
+_driver = None
+
+
+def client():
+    global _driver
+    if _driver is None:
+        _driver = AsyncGraphDatabase.driver(
+            settings.neo4j.uri,
+            auth=(settings.neo4j.user, settings.neo4j.password),
+            max_connection_pool_size=settings.neo4j.max_connection_pool_size,
+            connection_acquisition_timeout=settings.neo4j.connection_acquisition_timeout,
+            connection_timeout=settings.neo4j.connection_timeout,
+            max_transaction_retry_time=settings.neo4j.max_transaction_retry_time,
+        )
+    return _driver
+
+
+async def init_db() -> None:
+    client()  # 构造为懒连接，仅建出 driver 单例
+
+
+async def get_session():
+    """每次操作取一个轻量 pool 内 session；execute_read/write 自带事务重试。"""
+    async with client().session() as s:
+        yield s
+
+
+async def dispose() -> None:
+    global _driver
+    if _driver is not None:
+        await _driver.close()
+        _driver = None
+
+
+async def check_health() -> None:
+    await client().verify_connectivity()