Close 3 integration gaps between the ported Sandbox system and Agent V2:
1. Fix _invoke_tool_in_sandbox to use SandboxBashSession context manager
API correctly (keyword args, bash_tool, ToolReference), with graceful
fallback to direct invocation when DifyCli binary is unavailable.
2. Inject sandbox into run_context via _resolve_sandbox_context() in
WorkflowBasedAppRunner — automatically creates a sandbox when a
tenant has an active sandbox provider configured.
3. Register SandboxLayer in both advanced_chat and workflow app runners
for proper sandbox lifecycle cleanup on graph end.
Also: make SkillInitializer non-fatal when no skill bundle exists,
add node_id to ExecutionContext for sandbox session scoping.
Made-with: Cursor