Extends the live deploy console to remote/agent stacks. New agent WS endpoint
`/agent/ws/deploy/{stack_id}` runs `compose up -d` and streams its output; the
central app proxies it through `/ws/agent-deploy/{agent_id}/{stack_id}` (same
pattern + token URL-encoding as the agent-logs proxy) and records an
`agent.stack.start` audit entry. The editor's remote Deploy path now opens the
DeployConsole (agentId) instead of the blocking `agentsApi.action(start)`.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>