Refactor trip planning: DAG router + trip options UI + simplified itinerary

- Replace O(2^n) GeographicRouteExplorer with O(n) GameDAGRouter using DAG + beam search
- Add geographic diversity to route selection (returns routes from distinct regions)
- Add trip options selector UI (TripOptionsView, TripOptionCard) to choose between routes
- Simplify itinerary display: separate games and travel segments by date
- Remove complex ItineraryDay bundling, query games/travel directly per day
- Update ScenarioA/B/C planners to use GameDAGRouter
- Add new test suites for planners and travel estimator

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

SportsTime/Planning/Engine/ScenarioCPlanner.swift

@@ -194,8 +194,8 @@ final class ScenarioCPlanner: ScenarioPlanner {
 
             guard !gamesInRange.isEmpty else { continue }
 
-            // Use GeographicRouteExplorer to find sensible routes
-            let validRoutes = GeographicRouteExplorer.findAllSensibleRoutes(
+            // Use GameDAGRouter for polynomial-time beam search
+            let validRoutes = GameDAGRouter.findAllSensibleRoutes(
                 from: gamesInRange,
                 stadiums: request.stadiums,
                 anchorGameIds: [],  // No anchors in Scenario C