A deployment's identity becomes (name, kind), so a tool, service, and job can
share a name (a `backup` trio). Kind is structural — which per-kind store / dir —
not a derived discriminator threaded around.
- CastleConfig holds per-kind stores (services/jobs/tools/statics/references);
all_deployments()/deployments_named()/deployment(kind,name) replace the single
flat `deployments` dict. A construction-only `deployments` InitVar routes a flat
map into the stores by kind_for.
- Storage: deployments/<store>/<name>.yaml (per-kind dirs), with read-compat for
the old flat + services/+jobs/ layouts.
- Registry keyed by composite "<kind>/<name>" + name field; get()/all()/named()/put().
- Job units carry a -job marker (castle-<name>-job.{service,timer}); services and
everything else unchanged — so a service and a job can coexist.
- deploy/apply/lifecycle thread kind through unit naming, activate/deactivate,
is_active; caddyfile/tunnel/relations iterate via all_deployments/registry.all.
- Subdomain uniqueness validated across kinds (a service and a static can't share one).
182 core tests pass, incl. a new same-name-trio suite (round-trip, distinct units,
subdomain guard). API/CLI/UI updated in follow-up phases.