Adopt React Query and live updates across all UI pages

Replace custom useApi/useAgents hooks with @tanstack/react-query.
Add LiveUpdatesProvider for WebSocket-driven cache invalidation.
Add queryKeys module for centralized cache key management. Rework
all pages and dialogs to use React Query mutations and queries.
Improve CompanyContext with query-based data fetching.

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

ui/src/api/agents.ts

@@ -21,4 +21,14 @@ export const agentsApi = {
   terminate: (id: string) => api.post<Agent>(`/agents/${id}/terminate`, {}),
   createKey: (id: string, name: string) => api.post<AgentKeyCreated>(`/agents/${id}/keys`, { name }),
   invoke: (id: string) => api.post<HeartbeatRun>(`/agents/${id}/heartbeat/invoke`, {}),
+  wakeup: (
+    id: string,
+    data: {
+      source?: "timer" | "assignment" | "on_demand" | "automation";
+      triggerDetail?: "manual" | "ping" | "callback" | "system";
+      reason?: string | null;
+      payload?: Record<string, unknown> | null;
+      idempotencyKey?: string | null;
+    },
+  ) => api.post<HeartbeatRun | { status: "skipped" }>(`/agents/${id}/wakeup`, data),
 };