feat(routes): add realtime estimates panel with pattern-aware styling

- New GET /api/stops/estimates endpoint (nano mode: tripId, patternId, estimate, delay only)
- useStopEstimates hook wiring estimates to routes-$id stop panel
- Pattern-aware styling: dim schedules and estimates from other patterns
- Past scheduled departures shown with strikethrough instead of hidden
- Persist selected pattern in URL hash (replace navigation, no history push)
- Fix planner arrivals using new estimates endpoint

1 files changed, 18 insertions, 3 deletions

diff --git a/src/frontend/app/hooks/useArrivals.ts b/src/frontend/app/hooks/useArrivals.ts
index e86a0bf..530ebc4 100644
--- a/src/frontend/app/hooks/useArrivals.ts
+++ b/src/frontend/app/hooks/useArrivals.ts
@@ -1,5 +1,5 @@
 import { useQuery } from "@tanstack/react-query";
-import { fetchArrivals } from "../api/arrivals";
+import { fetchArrivals, fetchEstimates } from "../api/arrivals";
 
 export const useStopArrivals = (
   stopId: string,
@@ -10,7 +10,22 @@ export const useStopArrivals = (
     queryKey: ["arrivals", stopId, reduced],
     queryFn: () => fetchArrivals(stopId, reduced),
     enabled: !!stopId && enabled,
-    refetchInterval: 15000, // Refresh every 15 seconds
-    retry: false, // Disable retries to see errors immediately
+    refetchInterval: 15000,
+    retry: false,
+  });
+};
+
+export const useStopEstimates = (
+  stopId: string,
+  routeId: string,
+  viaStopId?: string,
+  enabled: boolean = true
+) => {
+  return useQuery({
+    queryKey: ["estimates", stopId, routeId, viaStopId],
+    queryFn: () => fetchEstimates(stopId, routeId, viaStopId),
+    enabled: !!stopId && !!routeId && enabled,
+    refetchInterval: 15000,
+    retry: false,
   });
 };