feat(ui): add React Query hooks for data fetching

- Add useFeatures, useFeature, useAgentOutput for feature data
- Add useGitHubIssues, useGitHubPRs, useGitHubValidations, useGitHubIssueComments
- Add useClaudeUsage, useCodexUsage with polling intervals
- Add useRunningAgents, useRunningAgentsCount
- Add useWorktrees, useWorktreeInfo, useWorktreeStatus, useWorktreeDiffs
- Add useGlobalSettings, useProjectSettings, useCredentials
- Add useAvailableModels, useCodexModels, useOpencodeModels
- Add useSessions, useSessionHistory, useSessionQueue
- Add useIdeationPrompts, useIdeas
- Add CLI status queries (claude, cursor, codex, opencode, github)
- Add useCursorPermissionsQuery, useWorkspaceDirectories
- Add usePipelineConfig, useSpecFile, useSpecRegenerationStatus

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/ui/src/hooks/queries/use-running-agents.ts

@@ -0,0 +1,61 @@
+/**
+ * Running Agents Query Hook
+ *
+ * React Query hook for fetching currently running agents.
+ * This data is invalidated by WebSocket events when agents start/stop.
+ */
+
+import { useQuery } from '@tanstack/react-query';
+import { getElectronAPI, type RunningAgent } from '@/lib/electron';
+import { queryKeys } from '@/lib/query-keys';
+import { STALE_TIMES } from '@/lib/query-client';
+
+interface RunningAgentsResult {
+  agents: RunningAgent[];
+  count: number;
+}
+
+/**
+ * Fetch all currently running agents
+ *
+ * @returns Query result with running agents and total count
+ *
+ * @example
+ * ```tsx
+ * const { data, isLoading } = useRunningAgents();
+ * const { agents, count } = data ?? { agents: [], count: 0 };
+ * ```
+ */
+export function useRunningAgents() {
+  return useQuery({
+    queryKey: queryKeys.runningAgents.all(),
+    queryFn: async (): Promise<RunningAgentsResult> => {
+      const api = getElectronAPI();
+      const result = await api.runningAgents.getAll();
+      if (!result.success) {
+        throw new Error(result.error || 'Failed to fetch running agents');
+      }
+      return {
+        agents: result.runningAgents ?? [],
+        count: result.totalCount ?? 0,
+      };
+    },
+    staleTime: STALE_TIMES.RUNNING_AGENTS,
+    // Note: Don't use refetchInterval here - rely on WebSocket invalidation
+    // for real-time updates instead of polling
+  });
+}
+
+/**
+ * Get running agents count
+ * This is a selector that derives count from the main query
+ *
+ * @returns Query result with just the count
+ */
+export function useRunningAgentsCount() {
+  const query = useRunningAgents();
+  return {
+    ...query,
+    data: query.data?.count ?? 0,
+  };
+}