feat: improve planning engine travel handling, itinerary reordering, and scenario planners

Add TravelInfo initializers and city normalization helpers to fix repeat
city-pair disambiguation. Improve drag-and-drop reordering with segment
index tracking and source-row-aware zone calculation. Enhance all five
scenario planners with better next-day departure handling and travel
segment placement. Add comprehensive tests across all planners.

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

SportsTimeTests/Planning/GameDAGRouterTests.swift

@@ -353,6 +353,36 @@ struct GameDAGRouterTests {
         #expect(!combinedRoutes.isEmpty, "NYC to Chicago over 2 days should be feasible")
     }
 
+    @Test("findRoutes: anchor routes can span gaps larger than 5 days")
+    func findRoutes_anchorRoutesAllowLongDateGaps() {
+        let today = calendar.startOfDay(for: Date())
+        let day0 = today
+        let day1 = calendar.date(byAdding: .day, value: 1, to: today)!
+        let day8 = calendar.date(byAdding: .day, value: 8, to: today)!
+
+        let sharedStadium = makeStadium(city: "New York", coord: nycCoord)
+        let bridgeStadium = makeStadium(city: "Boston", coord: bostonCoord)
+
+        let anchorStart = makeGame(stadiumId: sharedStadium.id, date: day0)
+        let bridgeGame = makeGame(stadiumId: bridgeStadium.id, date: day1)
+        let anchorEnd = makeGame(stadiumId: sharedStadium.id, date: day8)
+
+        let routes = GameDAGRouter.findRoutes(
+            games: [anchorStart, bridgeGame, anchorEnd],
+            stadiums: [sharedStadium.id: sharedStadium, bridgeStadium.id: bridgeStadium],
+            constraints: constraints,
+            anchorGameIds: [anchorStart.id, anchorEnd.id]
+        )
+
+        #expect(!routes.isEmpty, "Expected a route that includes both anchors across an 8-day gap")
+
+        for route in routes {
+            let ids = Set(route.map { $0.id })
+            #expect(ids.contains(anchorStart.id), "Route should include start anchor")
+            #expect(ids.contains(anchorEnd.id), "Route should include end anchor")
+        }
+    }
+
     // MARK: - Property Tests
 
     @Test("Property: route count never exceeds maxOptions (75)")