Function teardown 

pub async fn teardown(
    mcp_arcs: Vec<Arc<McpClient>>,
    network: Option<NetworkInterceptor>,
    container: Container,
    store: &SessionStore,
    sid: &SessionId,
    final_exit: i32,
)

Cleanup tail. Order: MCP shutdowns (so their podman exec pipes drain before the container goes away) -> container stop -> session finalize. Each step’s failure is logged but never propagated; the caller’s outcome owns the process exit code.

Callers must drop any Arc<McpClient> clones (e.g. tool adapters) and the agent before invoking this – otherwise Arc::try_unwrap returns Err and the explicit shutdown is skipped in favor of Drop.