feat: Rewrite agents (#2232)

letta/orm/__init__.py

@@ -1,3 +1,4 @@
+from letta.orm.agent import Agent
 from letta.orm.agents_tags import AgentsTags
 from letta.orm.base import Base
 from letta.orm.block import Block
@@ -9,6 +10,7 @@ from letta.orm.organization import Organization
 from letta.orm.passage import Passage
 from letta.orm.sandbox_config import SandboxConfig, SandboxEnvironmentVariable
 from letta.orm.source import Source
+from letta.orm.sources_agents import SourcesAgents
 from letta.orm.tool import Tool
 from letta.orm.tools_agents import ToolsAgents
 from letta.orm.user import User