feat(planning): add trip filtering and fix departure date logic

- Add Trip.status property for status tracking
- Add RouteFilters trip list methods (filterBySport, filterByDateRange, filterByStatus, applyFilters)
- Add TravelEstimator max driving hours validation
- Fix ScenarioA/B departureDate to use last game day (not day after)
- Update GameDAGRouter comments for buffer logic

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

SportsTime/Planning/Engine/GameDAGRouter.swift

@@ -519,15 +519,17 @@ enum GameDAGRouter {
             to: calendar.startOfDay(for: to.startTime)
         ).day ?? 0
 
-        // For same-day games (doubleheaders), use shorter buffers
-        // People leave earlier and arrive closer to game time
+        // Buffer logic:
+        // - Same stadium same day: 2hr post-game (doubleheader)
+        // - Different stadiums same day: 2hr post-game (regional day trip)
+        // - Different days: 3hr post-game (standard multi-day trip)
         let postGameBuffer: Double
         let preGameBuffer: Double
 
         if daysBetween == 0 {
-            // Same-day doubleheader: leave during game, arrive at game time
-            postGameBuffer = 2.0  // Leave during/right after game
-            preGameBuffer = 0.5   // Arrive closer to start time
+            // Same-day games: use shorter buffers (doubleheader or day trip)
+            postGameBuffer = 2.0  // Leave 2 hours after first game
+            preGameBuffer = 0.5   // Arrive 30min before next game
         } else {
             // Different days: use standard buffers
             postGameBuffer = gameEndBufferHours  // 3.0 hours