Phase 11: remote UX & network attach (0.11.0)

- Live remote-stack logs over a WebSocket proxied through the central app to
  the agent (/ws/agent-logs/{agent}/{stack}); agent gains a WS log endpoint.
- Deploy to a remote host from the UI: host selector in the New Stack editor
  and template dialog; templates instantiate onto an agent via the proxy.
- Network attach/detach: expandable inspect view per network with
  connect/disconnect + container picker; GET /{id}/containers, POST connect/disconnect.
- Remove dead pages/Placeholder.tsx.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/pages/RemoteStackDetail.tsx

@@ -14,6 +14,7 @@ import {
 import { toast } from "sonner";
 import { Badge, Button, Card, Spinner, StatusDot } from "@/components/ui";
 import { HostDot } from "@/components/hosts/HostDot";
+import { LogViewer } from "@/components/stacks/LogViewer";
 import { BackupButton } from "@/components/stacks/BackupRestore";
 import { agentsApi } from "@/api/agents";
 import { apiErrorMessage } from "@/api/client";
@@ -116,7 +117,11 @@ export function RemoteStackDetail() {
 
       <div className="flex-1 overflow-hidden">
         {tab === "Overview" && <Overview containers={data.containers} />}
-        {tab === "Logs" && <RemoteLogs agentId={aid} stackId={id} />}
+        {tab === "Logs" && (
+          <Card className="h-full overflow-hidden">
+            <LogViewer stackId={id} agentId={aid} />
+          </Card>
+        )}
         {tab === "Environment" && (
           <RemoteEditor
             agentId={aid}
@@ -169,30 +174,6 @@ function Overview({ containers }: { containers: any[] }) {
   );
 }
 
-function RemoteLogs({ agentId, stackId }: { agentId: number; stackId: string }) {
-  const { data, isLoading, refetch, isFetching } = useQuery({
-    queryKey: ["agent-logs", agentId, stackId],
-    queryFn: () => agentsApi.logs(agentId, stackId, 400),
-    refetchInterval: 5000,
-  });
-  return (
-    <Card className="flex h-full flex-col overflow-hidden">
-      <div className="mb-2 flex justify-end">
-        <Button variant="ghost" onClick={() => refetch()} loading={isFetching}>
-          Refresh
-        </Button>
-      </div>
-      {isLoading ? (
-        <Spinner />
-      ) : (
-        <pre className="flex-1 overflow-auto whitespace-pre-wrap break-all bg-slate-950 p-3 font-mono text-xs text-slate-100">
-          {data?.logs || "No logs."}
-        </pre>
-      )}
-    </Card>
-  );
-}
-
 function RemoteEditor({
   agentId,
   stackId,