feat: Add support for 2018 client API endpoints and data models

- Implemented new search endpoints for rooms to accommodate the 2018 client.
- Added support for retrieving room details and featured rooms in a format compatible with the 2018 client.
- Introduced new data models for login responses and player presence specific to the 2018 client.
- Created mappers to convert between internal entities and the 2018 wire formats for players and rooms.
- Updated existing storefront APIs to include versioned endpoints for the 2018 client.
- Enhanced the version controller to return dual-format responses for compatibility with both 2018 and 2020 clients.
- Refactored the configuration service to ensure trailing slashes in URLs for the 2018 client.

DorkNet.Server/Compat2018/Player2018Mapper.cs

@@ -0,0 +1,30 @@
+using DorkNet.Models.Auth;
+using DorkNet.Server.Data.Entities;
+
+namespace DorkNet.Server.Compat2018;
+
+/// <summary>
+/// Maps a <see cref="PlayerEntity"/> to the June-2018 wire player object
+/// (<see cref="Player2018"/>). Lives in the server (not DorkNet.Models) because
+/// the DTO project can't reference the data-layer entity. Shared by the
+/// platformlogin/v1, players/v1, and presence controllers so the 2018 player
+/// shape is produced in exactly one place.
+/// Keys verified against RecNet.EEBPLECPEGD.Deserialize (RecNet.cs:64632).
+/// </summary>
+public static class Player2018Mapper
+{
+    public static Player2018 From(PlayerEntity p) => new()
+    {
+        Id = p.Id,
+        Username = p.Username,
+        DisplayName = string.IsNullOrEmpty(p.DisplayName) ? p.Username : p.DisplayName,
+        Bio = p.Bio ?? string.Empty,
+        XP = p.XP,
+        Level = p.Level,
+        Developer = p.IsDeveloper,
+        CanReceiveInvites = p.CanReceiveInvites,
+        ProfileImageName = p.ProfileImageName ?? string.Empty,
+        JuniorProfile = p.IsJunior,
+        HasBirthday = p.Birthday.HasValue,
+    };
+}