Add TFR warning banner for airspace restrictions

Fetches active Temporary Flight Restrictions from the FAA website,
filters by configured state (LOCATION_STATE env var), and displays
a red warning banner at the top of the dashboard when TFRs are present.
Data is cached for 30 minutes and degrades gracefully if the FAA is unreachable.

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

frontend/app/page.tsx

@@ -1,12 +1,13 @@
 'use client'
 
-import { useCurrentWeather, useForecast, useHistorical } from '@/hooks/use-weather'
+import { useCurrentWeather, useForecast, useHistorical, useTfrs } from '@/hooks/use-weather'
 import { AssessmentBadge } from '@/components/weather/assessment-badge'
 import { WindSpeedChart } from '@/components/weather/wind-speed-chart'
 import { WindDirectionChart } from '@/components/weather/wind-direction-chart'
 import { ThresholdControls } from '@/components/weather/threshold-controls'
 import { RefreshCountdown } from '@/components/weather/refresh-countdown'
 import { StaleDataBanner } from '@/components/weather/stale-data-banner'
+import { TfrBanner } from '@/components/weather/tfr-banner'
 import { Collapsible } from '@/components/ui/collapsible'
 import { useQueryClient } from '@tanstack/react-query'
 import { Loader2, AlertCircle } from 'lucide-react'
@@ -28,6 +29,9 @@ export default function DashboardPage() {
     error: forecastError,
   } = useForecast()
 
+  // Fetch TFR data
+  const { data: tfrData } = useTfrs()
+
   // Fetch yesterday's data for comparison
   const yesterday = format(subDays(new Date(), 1), 'yyyy-MM-dd')
   const {
@@ -111,6 +115,11 @@ export default function DashboardPage() {
           )}
         </div>
 
+        {/* TFR Warning */}
+        {tfrData && tfrData.tfrs.length > 0 && (
+          <TfrBanner tfrs={tfrData.tfrs} />
+        )}
+
         {/* Stale Data Warning */}
         <StaleDataBanner lastUpdated={currentWeather.last_updated} />