feat: add TypeScript types, API client, and TanStack Query hooks

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

TaskTracker.Web/src/api/context.ts

@@ -0,0 +1,19 @@
+import { useQuery } from '@tanstack/react-query'
+import { request } from './client'
+import type { ContextEvent, ContextSummaryItem } from '../types'
+
+export function useRecentContext(minutes = 30) {
+  return useQuery({
+    queryKey: ['context', 'recent', minutes],
+    queryFn: () => request<ContextEvent[]>({ url: '/context/recent', params: { minutes } }),
+    refetchInterval: 60_000,
+  })
+}
+
+export function useContextSummary() {
+  return useQuery({
+    queryKey: ['context', 'summary'],
+    queryFn: () => request<ContextSummaryItem[]>({ url: '/context/summary' }),
+    refetchInterval: 60_000,
+  })
+}