调整代码，支持项目切换，打开不同数据库的连接

app/infra/db/postgresql/database.py

@@ -17,7 +17,9 @@ class Database:
     def init_pool(self, db_name=None):
         """Initialize the connection pool."""
         # Use provided db_name, or the one from constructor, or default from config
-        conn_string = postgresql_info.get_pgconn_string()
+        target_db_name = db_name or self.db_name
+        conn_string = postgresql_info.get_pgconn_string(db_name=target_db_name)
+            
         try:
             self.pool = psycopg_pool.AsyncConnectionPool(
                 conninfo=conn_string,
@@ -26,7 +28,7 @@ class Database:
                 open=False,  # Don't open immediately, wait for startup
                 kwargs={"row_factory": dict_row},  # Return rows as dictionaries
             )
-            logger.info(f"PostgreSQL connection pool initialized for database: default")
+            logger.info(f"PostgreSQL connection pool initialized for database: {target_db_name or 'default'}")
         except Exception as e:
             logger.error(f"Failed to initialize postgresql connection pool: {e}")
             raise