gateway: converge, don't start/stop/reload

The gateway is a deployment (castle-gateway) — its lifecycle is the same
convergence as everything else, so the bespoke start/stop/reload verbs
(which still routed through the retired enable/disable path) are gone.

- CLI: `castle gateway` is now inspection only — bare or `status` shows
  the route table. Start/stop/reload it via `castle apply` (render routes
  + reload) or `castle restart castle-gateway`. Deletes the last users of
  `_service_enable`/`_service_disable`, so those are removed too.
- API: retire `POST /gateway/reload` (making routes live is `POST /apply`);
  `PUT /gateway/config` message + docstring now say apply, not deploy.
- UI: GatewayPanel's "Reload" button → "Apply" (useApply); drop the
  useGatewayReload hook; GatewaySettings points at `castle apply`.
- docs: `castle gateway reload|status` → `castle gateway` (status lens).

core 129 / cli 31 / api 59 pass; dashboard builds clean; live `castle
gateway` shows routes with no start/stop/reload; /gateway/reload removed
from the API.

app/src/components/GatewayPanel.tsx

@@ -2,7 +2,7 @@ import { useMemo, useState } from "react"
 import { Link } from "react-router-dom"
 import { Globe, RefreshCw, FileText, ExternalLink, Cable } from "lucide-react"
 import type { GatewayInfo, HealthStatus } from "@/types"
-import { useGatewayReload, useCaddyfile } from "@/services/api/hooks"
+import { useApply, useCaddyfile } from "@/services/api/hooks"
 import { subdomainUrl } from "@/lib/labels"
 import { HealthBadge } from "./HealthBadge"
 import { GatewaySettings } from "./GatewaySettings"
@@ -14,7 +14,7 @@ interface GatewayPanelProps {
 
 export function GatewayPanel({ gateway, statuses }: GatewayPanelProps) {
   const statusMap = new Map(statuses.map((s) => [s.id, s]))
-  const { mutate: reload, isPending: reloading } = useGatewayReload()
+  const { mutate: apply, isPending: applying } = useApply()
   const [showCaddyfile, setShowCaddyfile] = useState(false)
   const { data: caddyfileData } = useCaddyfile(showCaddyfile)
 
@@ -36,13 +36,13 @@ export function GatewayPanel({ gateway, statuses }: GatewayPanelProps) {
         </div>
         <div className="flex items-center gap-1">
           <button
-            onClick={() => reload()}
-            disabled={reloading}
+            onClick={() => apply({})}
+            disabled={applying}
             className="flex items-center gap-1 text-xs px-2.5 py-1 rounded bg-[var(--border)] hover:bg-[var(--border)]/80 text-[var(--muted)] hover:text-[var(--foreground)] transition-colors disabled:opacity-40"
-            title="Regenerate Caddyfile and reload Caddy"
+            title="Converge: regenerate routes and reload the gateway"
           >
-            <RefreshCw size={12} className={reloading ? "animate-spin" : ""} />
-            Reload
+            <RefreshCw size={12} className={applying ? "animate-spin" : ""} />
+            Apply
           </button>
           <button
             onClick={() => setShowCaddyfile((v) => !v)}

app/src/components/GatewaySettings.tsx

@@ -4,7 +4,7 @@ import type { GatewayInfo } from "@/types"
 import { useSaveGatewayConfig } from "@/services/api/hooks"
 
 /** Editable gateway routing + public-exposure settings (domain / public_domain /
- *  tunnel / tls). Saves to castle.yaml; changes take effect on the next deploy. */
+ *  tunnel / tls). Saves to castle.yaml; changes take effect on the next apply. */
 export function GatewaySettings({ gateway }: { gateway: GatewayInfo }) {
   const { mutate: save, isPending, data: saved } = useSaveGatewayConfig()
   const [editing, setEditing] = useState(false)
@@ -44,7 +44,7 @@ export function GatewaySettings({ gateway }: { gateway: GatewayInfo }) {
           <button onClick={() => setEditing(false)} className="flex items-center gap-1 text-xs px-2.5 py-1 rounded bg-[var(--border)] text-[var(--muted)]">
             <X size={12} /> Cancel
           </button>
-          <span className="text-xs text-[var(--muted)]">Run <span className="font-mono">castle deploy</span> to apply.</span>
+          <span className="text-xs text-[var(--muted)]">Run <span className="font-mono">castle apply</span> (or the Apply button) to converge.</span>
         </div>
       </div>
     )