feat: Add companion agent one-click deployment + fix frontend TS errors

Go deployment orchestrator with platform-specific SteamCMD install,
Rust server download, server.cfg generation, and service registration.
Wire deploy command subscription in daemon, make GameServerPath optional,
add InstallDir config with OS-aware defaults. Fix unused imports and
WebSocket subscribe API in ServerView.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/views/admin/ServerView.vue

@@ -17,8 +17,6 @@ import {
   Rocket,
   AlertTriangle,
   Check,
-  ClipboardCopy,
-  ChevronRight,
 } from 'lucide-vue-next'
 import type { DeploymentConfig, DeploymentStatus } from '@/types'
 import { useWebSocket } from '@/composables/useWebSocket'
@@ -194,9 +192,9 @@ onMounted(async () => {
   loadFormFromConfig()
 
   const ws = useWebSocket()
-  ws.on('event', (data: any) => {
-    if (data.event === 'deploy_status') {
-      server.updateDeploymentStatus(data.data as DeploymentStatus)
+  ws.subscribe((msg) => {
+    if (msg.type === 'event' && msg.event === 'deploy_status') {
+      server.updateDeploymentStatus(msg.data as DeploymentStatus)
     }
   })
 })