feat(bp): /battle_pass/info — service + controller + 3 tests

Also fixes BattlePassRepository.GetActiveSeasonAsync to use client-side
DateTimeOffset filtering (SQLite provider cannot translate DateTimeOffset
comparisons in LINQ WHERE/ORDER BY clauses).

SVSim.EmulatedEntrypoint/Controllers/BattlePassController.cs

@@ -0,0 +1,31 @@
+using Microsoft.AspNetCore.Mvc;
+using SVSim.EmulatedEntrypoint.Models.Dtos.BattlePass;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;
+using SVSim.EmulatedEntrypoint.Services;
+
+namespace SVSim.EmulatedEntrypoint.Controllers;
+
+/// <summary>
+/// /battle_pass/* — season metadata, premium-pass purchase. Wire shapes mirror
+/// Wizard/BattlePass{Info,PurchaseInfo,Buy}Task.cs.
+/// </summary>
+[Route("battle_pass")]
+public class BattlePassController : SVSimController
+{
+    private readonly IBattlePassService _battlePass;
+
+    public BattlePassController(IBattlePassService battlePass)
+    {
+        _battlePass = battlePass;
+    }
+
+    [HttpPost("info")]
+    public async Task<IActionResult> Info(BaseRequest request, CancellationToken ct)
+    {
+        if (!TryGetViewerId(out long viewerId)) return Unauthorized();
+
+        var info = await _battlePass.GetInfoAsync(viewerId, ct);
+        if (info is null) return Ok(new { }); // off-season: empty payload
+        return Ok(info);
+    }
+}