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/ScenarioCPlannerTests.swift

@@ -197,6 +197,47 @@ struct ScenarioCPlannerTests {
         #expect(failure.reason == .noGamesInRange)
     }
 
+    @Test("plan: city names with state suffixes match stadium city names")
+    func plan_cityNamesWithStateSuffixes_matchStadiumCities() {
+        let baseDate = Date()
+        let endDate = baseDate.addingTimeInterval(86400 * 10)
+
+        let startLocation = LocationInput(name: "Chicago, IL", coordinate: chicagoCoord)
+        let endLocation = LocationInput(name: "New York, NY", coordinate: nycCoord)
+
+        let chicagoStadium = makeStadium(id: "chicago", city: "Chicago", coordinate: chicagoCoord)
+        let nycStadium = makeStadium(id: "nyc", city: "New York", coordinate: nycCoord)
+
+        let chicagoGame = makeGame(id: "chi-game", stadiumId: "chicago", dateTime: baseDate.addingTimeInterval(86400 * 1))
+        let nycGame = makeGame(id: "nyc-game", stadiumId: "nyc", dateTime: baseDate.addingTimeInterval(86400 * 4))
+
+        let prefs = TripPreferences(
+            planningMode: .locations,
+            startLocation: startLocation,
+            endLocation: endLocation,
+            sports: [.mlb],
+            startDate: baseDate,
+            endDate: endDate,
+            leisureLevel: .moderate,
+            lodgingType: .hotel,
+            numberOfDrivers: 2
+        )
+
+        let request = PlanningRequest(
+            preferences: prefs,
+            availableGames: [chicagoGame, nycGame],
+            teams: [:],
+            stadiums: ["chicago": chicagoStadium, "nyc": nycStadium]
+        )
+
+        let result = planner.plan(request: request)
+
+        guard case .success = result else {
+            Issue.record("Expected success with city/state location labels matching plain stadium cities")
+            return
+        }
+    }
+
     // MARK: - Specification Tests: Directional Filtering
 
     @Test("plan: directional filtering includes stadiums toward destination")