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/Domain/TravelInfoTests.swift

@@ -0,0 +1,51 @@
+//
+//  TravelInfoTests.swift
+//  SportsTimeTests
+//
+//  Tests for canonical TravelInfo construction and city matching.
+//
+
+import Testing
+@testable import SportsTime
+
+@Suite("TravelInfo")
+struct TravelInfoTests {
+
+    private func makeSegment(from: String, to: String) -> TravelSegment {
+        TravelSegment(
+            fromLocation: LocationInput(name: from),
+            toLocation: LocationInput(name: to),
+            travelMode: .drive,
+            distanceMeters: 120_000,
+            durationSeconds: 7_200
+        )
+    }
+
+    @Test("init(segment:) derives canonical city pair and metrics")
+    func initFromSegment() {
+        let segment = makeSegment(from: "Detroit", to: "Chicago")
+        let info = TravelInfo(segment: segment, segmentIndex: 2)
+
+        #expect(info.fromCity == "Detroit")
+        #expect(info.toCity == "Chicago")
+        #expect(info.segmentIndex == 2)
+        #expect(info.distanceMeters == segment.distanceMeters)
+        #expect(info.durationSeconds == segment.durationSeconds)
+    }
+
+    @Test("normalizeCityName trims and lowercases")
+    func normalizeCityName() {
+        #expect(TravelInfo.normalizeCityName("  New York  ") == "new york")
+    }
+
+    @Test("matches(segment:) uses normalized city comparison")
+    func matchesSegment() {
+        let segment = makeSegment(from: "Seattle", to: "Portland")
+        let info = TravelInfo(fromCity: "  seattle ", toCity: "PORTLAND  ")
+
+        #expect(info.matches(segment: segment))
+        #expect(info.matches(from: "SEATTLE", to: "portland"))
+        #expect(!info.matches(from: "Seattle", to: "San Francisco"))
+    }
+}
+