feat(domain): add AnySport conformance to Sport enum

Existing Sport enum now conforms to AnySport protocol, enabling
unified handling with future DynamicSport types.

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

SportsTimeTests/Domain/SportTests.swift

@@ -0,0 +1,53 @@
+//
+//  SportTests.swift
+//  SportsTimeTests
+//
+
+import Foundation
+import Testing
+@testable import SportsTime
+
+@Suite("Sport AnySport Conformance")
+struct SportAnySportTests {
+
+    @Test("Sport conforms to AnySport protocol")
+    func sportConformsToAnySport() {
+        let sport: any AnySport = Sport.mlb
+        #expect(sport.sportId == "MLB")
+        #expect(sport.displayName == "Major League Baseball")
+        #expect(sport.iconName == "baseball.fill")
+    }
+
+    @Test("Sport.id equals Sport.sportId")
+    func sportIdEqualsSportId() {
+        for sport in Sport.allCases {
+            #expect(sport.id == sport.sportId)
+        }
+    }
+
+    @Test("Sport isInSeason works correctly")
+    func sportIsInSeason() {
+        let mlb = Sport.mlb
+
+        // April is in MLB season (March-October)
+        let april = Calendar.current.date(from: DateComponents(year: 2026, month: 4, day: 15))!
+        #expect(mlb.isInSeason(for: april))
+
+        // January is not in MLB season
+        let january = Calendar.current.date(from: DateComponents(year: 2026, month: 1, day: 15))!
+        #expect(!mlb.isInSeason(for: january))
+    }
+
+    @Test("Sport with wrap-around season works correctly")
+    func sportWrapAroundSeason() {
+        let nba = Sport.nba
+
+        // December is in NBA season (October-June wraps)
+        let december = Calendar.current.date(from: DateComponents(year: 2026, month: 12, day: 15))!
+        #expect(nba.isInSeason(for: december))
+
+        // July is not in NBA season
+        let july = Calendar.current.date(from: DateComponents(year: 2026, month: 7, day: 15))!
+        #expect(!nba.isInSeason(for: july))
+    }
+}