feat: support sandbox env for inference

configs/agents/examples/sandbox/it_asset_demo.yaml

@@ -0,0 +1,24 @@
+# @package _global_
+defaults:
+  - /model/base@model
+  - _self_
+
+agent:
+  name: sandbox-4s-agent
+  instructions: |-
+    You are a careful assistant for 4S service appointments.
+    Use the provided tools to query and update appointment records.
+    Return concise answers and ensure tool calls follow the schema.
+
+env:
+  name: sandbox
+  config:
+    # Sandbox type selector for multi-implementation support.
+    sandbox_type: ""    # envscale
+    # Online sandbox endpoint and access token.
+    base_url: ""
+    run_id_source: explicit
+    run_id: ""
+    data_dir: ""
+    access_token: ""
+    timeout: 60

utu/env/__init__.py

@@ -4,6 +4,7 @@
 from .browser_env_e2b import BrowserE2BEnv
 from .browser_tione_env import BrowserTioneEnv
 from .e2b_env import E2BEnv
+from .sandbox_env import SandboxEnv
 from .shell_local_env import ShellLocalEnv
 
 
@@ -23,5 +24,8 @@ async def get_env(config: AgentConfig, trace_id: str) -> _BaseEnv:
             return BrowserE2BEnv(config.env.config)
         case "browser_tione":
             return BrowserTioneEnv(config.env.config)
+        case "sandbox":
+            # Sandbox type is configured via env.config.sandbox_type.
+            return SandboxEnv(config.env.config, trace_id)
         case _:
             raise ValueError(f"Unknown env name: {config.env.name}")