Introduce V5Feature and config so V5 routes, jobs, commands, morph maps,
and model queries run only when enabled. Move V5 migrations to
migrations-v5 (loaded only when enabled), remove Flux from production
Docker/install paths, and add isolation tests.
Add Flux agent token issuing, open and revoke Caddy ingress firewall
rules, broadcast server-scoped application status updates, and update
the dashboard to show unreachable servers as unknown.
Add scripts and Lima config for managing local coold endpoint VMs,
mint Flux dev host JWTs, expose coold host details on the V5 home
page, and document the local development workflow.
