Add a graceful Shutdown action alongside Proxmox's Start/Restart/Stop

Stop maps to Proxmox's hard power-off (/status/stop) — fine for a
crashed guest, but risky for anything with a filesystem that'd rather
flush cleanly first. Proxmox exposes a separate /status/shutdown
endpoint that asks the guest to power itself down (ACPI event for a
VM, SIGTERM-then-wait for a container), so add it as its own action
rather than overloading Stop.

- New shutdownGuest() on the Proxmox adapter, calling /status/shutdown.
- The existing generic action route/loop already dispatches by
  ${action}Guest, so adding "shutdown" to that list was enough on the
  server side — no new route needed.
- New Shutdown button next to Restart/Stop on both the Integrations
  page's guest table and a Proxmox-linked server's detail page.
  Stop's confirm prompt now explicitly points at Shutdown as the
  gentler alternative.

Verified end-to-end against a mock Proxmox server: the shutdown call
hits /status/shutdown (never /status/stop) and is audit-logged as
shutdown_guest.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

server/src/integrations/proxmox/adapter.ts

@@ -62,6 +62,8 @@ export interface ProxmoxAdapter {
   startGuest(node: string, type: ProxmoxGuestType, vmid: number): Promise<void>;
   stopGuest(node: string, type: ProxmoxGuestType, vmid: number): Promise<void>;
   restartGuest(node: string, type: ProxmoxGuestType, vmid: number): Promise<void>;
+  /** Graceful shutdown (ACPI power event for a VM, SIGTERM-then-wait for a container) — unlike stopGuest, this asks the guest OS to shut itself down. */
+  shutdownGuest(node: string, type: ProxmoxGuestType, vmid: number): Promise<void>;
 }
 
 function parseSizeToBytes(size: string): number | null {
@@ -267,6 +269,7 @@ export function createProxmoxAdapter(config: ProxmoxConfig): ProxmoxAdapter {
   const startGuest = (node: string, type: ProxmoxGuestType, vmid: number) => statusAction(node, type, vmid, "start");
   const stopGuest = (node: string, type: ProxmoxGuestType, vmid: number) => statusAction(node, type, vmid, "stop");
   const restartGuest = (node: string, type: ProxmoxGuestType, vmid: number) => statusAction(node, type, vmid, "reboot");
+  const shutdownGuest = (node: string, type: ProxmoxGuestType, vmid: number) => statusAction(node, type, vmid, "shutdown");
 
   async function ping(): Promise<{ ok: boolean; latencyMs?: number; error?: string }> {
     const start = Date.now();
@@ -278,5 +281,5 @@ export function createProxmoxAdapter(config: ProxmoxConfig): ProxmoxAdapter {
     }
   }
 
-  return { ping, listGuests, getGuestDetail, startGuest, stopGuest, restartGuest };
+  return { ping, listGuests, getGuestDetail, startGuest, stopGuest, restartGuest, shutdownGuest };
 }

server/src/routes/integrations.ts

@@ -627,7 +627,7 @@ integrationsRouter.get("/:id/proxmox/guests", asyncHandler(async (req, res) => {
   }
 }));
 
-const proxmoxActions = ["start", "stop", "restart"] as const;
+const proxmoxActions = ["start", "stop", "restart", "shutdown"] as const;
 
 for (const action of proxmoxActions) {
   integrationsRouter.post(