Add pkgroll build and harden sandbox/SSH flows
Update package.json to use dist module and add start:prod/build
(pkgroll).
Use consola for logging and mount SSH router under /ssh; rename connect
route and handle invalid JWTs gracefully. Improve sandbox creation with
provider API error handling, agent validation, and optional base
fallback.
Add DENO_SNAPSHOT_ROOT support and adjust PATH for Deno SSH. Wire
Terminal
onClose in the web UI.