fix(sandbox-adapter): agentos hosted vm errors

[eersnington]

Three fixes so agentOSProvider commands work in hosted agentOS VMs.

Problem	Fix
A VM whose boot failed stays failed, so every command fails.	On connect, check v1.vm.status and call v1.vm.restart when lifecycle is "failed".
A spawned process keeps stdin open, so a command that reads stdin waits forever.	Run each command as sh -c "exec </dev/null\n<command>".
agentOS fails a command that starts for the first time while another command runs in the same VM.	Run commands one at a time through a queue per sandbox.

// packages/sandbox-adapter/src/agentos.ts
let queue: Promise<unknown> = Promise.resolve();
return {
	exec: (command, options) => {
		const result = queue.then(() => run(command, options));
		queue = result.catch(() => {});
		return result;
	},
	// ...
};

• AgentOSActorHandle gains v1.vm.status and v1.vm.restart.
• A failed command does not block the queue: the queue continues after a rejection.

[railway-app]

This PR was not deployed automatically as @eersnington does not have access to the Railway project.

In order to get automatic PR deploys, please add @eersnington to your workspace on Railway.

[eersnington]

slopped checks