docs+install: sweep deploy/start → castle apply

Update the README, AGENTS.md, install.sh, and docs/ for the converge
model: one `castle apply [name] [--plan]` replaces `deploy && start` and
the per-kind enable/disable/install/start/stop verbs. CLI references now
list apply + restart (the imperative bounce) + logs; recipes use
`castle apply`; "turn it off" is documented as `enabled: false` + apply.
install.sh's next-steps collapse to a single `castle apply`.

Verified: no retired-verb command instructions remain in any markdown;
install.sh syntax OK; live `castle apply --plan` reports converged;
doctor all-green; core 129 / cli 31 / api 59 pass.

docs/stacks/react-vite.md

@@ -171,7 +171,7 @@ See @docs/registry.md for the full registry reference.
 ## Serving with Caddy
 
 For production, the static build output is served by Caddy rather than a Node
-process. You do **not** write this block by hand — `castle deploy` generates it.
+process. You do **not** write this block by hand — `castle apply` generates it.
 The flow:
 
 1. You build the frontend with `castle program build <name>` (deploy does **not**