feat: add session-scoped client tool waits

backend/schemas.py

@@ -26,6 +26,7 @@ McpTransport = Literal["streamable_http", "sse"]
 ToolParameterType = Literal["string", "number", "integer", "boolean", "object", "array"]
 ToolParameterLocation = Literal["path", "query", "body", "header"]
 ToolExecutionMode = Literal["immediate", "async"]
+ClientToolResponseWaitMode = Literal["timeout", "session"]
 DynamicVariableType = Literal["string", "number", "boolean"]
 
 # 外部应用类型:其 config.apiKey 是该助手私有密钥,读时打码 / 写时哨兵
@@ -228,6 +229,7 @@ class ClientToolConfig(CamelModel):
     allow_interruptions: bool = True
     execution_mode: ToolExecutionMode = "async"
     wait_for_response: bool = True
+    response_wait_mode: ClientToolResponseWaitMode = "timeout"
     parameters: list[ToolParameter] = Field(default_factory=list)
     timeout_seconds: int = Field(default=3, ge=1, le=30)
     dynamic_variable_assignments: dict[str, str] = Field(default_factory=dict)