Add SSH access support for sandboxes
Expose a /v1/sandboxes/:sandboxId/ssh endpoint and add BaseSandbox.ssh
so
providers can return SSH credentials. Implement ssh for daytona and deno
(and stub vercel). Update API SSH router to parse JWT/x-sandbox-id,
fetch provider SSH info, and connect using returned hostname/username.
Update types and wire Terminal UI to pass sandboxId and Authorization
headers when creating and managing SSH sessions