feat(http): stub /arena_colosseum/get_fee_info (is_colosseum_period:false)

SVSim.EmulatedEntrypoint/Controllers/ArenaColosseumController.cs

@@ -0,0 +1,22 @@
+using Microsoft.AspNetCore.Mvc;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests.ArenaColosseum;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Responses.ArenaColosseum;
+
+namespace SVSim.EmulatedEntrypoint.Controllers;
+
+/// <summary>
+/// Stub controller for the Colosseum arena family. Currently only emits a "no Colosseum
+/// period" /get_fee_info response so the home/arena screen doesn't 404. The full Colosseum
+/// flow (top, entry, register_deck, event_info, retire, finish, class_choose, card_choose,
+/// matchmaking) is deferred — see Wizard/ColosseumEntryInfoTask.cs for the parser surface.
+/// </summary>
+[Route("arena_colosseum")]
+public class ArenaColosseumController : SVSimController
+{
+    [HttpPost("get_fee_info")]
+    public IActionResult GetFeeInfo([FromBody] GetFeeInfoRequest req)
+    {
+        if (!TryGetViewerId(out _)) return Unauthorized();
+        return Ok(new GetFeeInfoResponseDto());
+    }
+}