feat(rank-battle): RankBattleController shell + DTOs + routing smoke tests

Stands up the controller with all 13 rank-battle URL routes wired via
explicit absolute [HttpPost] attributes (multi-prefix family — can't ride
[Route(\"[controller]\")]). Real DoMatching / AiStart logic arrives in
later tasks; finish + telemetry + force-finish are returnable stubs as
of this task.

DTOs cover the request + response shapes per the spec. Note the
camelCase wire keys on AiBattlePlayerInfo (sleeveId, emblemId, ...) —
the AI battle subsystem uses camelCase, not the project-default
snake_case, per AIBattleStartTask.Parse's literal Keys.Contains lookups.

DoMatchingResponseDto.NodeServerUrl is non-nullable + always-emit (with
[JsonIgnore(Never)]) — matches Phase 2's TK2 fix because the client's
DoMatchingBase parser calls .ToString() without a Keys.Contains guard.

13 routing smoke tests confirm each URL resolves to the controller.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Controllers/RankBattleController.cs

@@ -0,0 +1,125 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using SVSim.BattleNode.Bridge;
+using SVSim.Database.Enums;
+using SVSim.EmulatedEntrypoint.Constants;
+using SVSim.EmulatedEntrypoint.Matching;
+using SVSim.EmulatedEntrypoint.Models.Dtos.RankBattle;
+using SVSim.EmulatedEntrypoint.Security.SteamSessionAuthentication;
+using SVSim.EmulatedEntrypoint.Services;
+
+namespace SVSim.EmulatedEntrypoint.Controllers;
+
+/// <summary>
+/// Rank battle family — covers rotation/unlimited human PvP + AI variants. Crossover
+/// is out of scope (no AI variant; human-only). Multi-prefix URLs (rotation_rank_battle/,
+/// unlimited_rank_battle/, ai_*_rank_battle/, rank_battle/) require explicit absolute
+/// route attributes on each action; the controller doesn't extend SVSimController's
+/// [Route("[controller]")] convention.
+/// </summary>
+[ApiController]
+[Authorize(AuthenticationSchemes = SteamAuthenticationConstants.SchemeName)]
+public sealed class RankBattleController : ControllerBase
+{
+    private readonly IMatchingPairUpService _pairUp;
+    private readonly IMatchingBridge _bridge;
+    private readonly IMatchContextBuilder _ctxBuilder;
+    private readonly IBotRoster _botRoster;
+    private readonly ILogger<RankBattleController> _log;
+
+    public RankBattleController(
+        IMatchingPairUpService pairUp,
+        IMatchingBridge bridge,
+        IMatchContextBuilder ctxBuilder,
+        IBotRoster botRoster,
+        ILogger<RankBattleController> log)
+    {
+        _pairUp = pairUp;
+        _bridge = bridge;
+        _ctxBuilder = ctxBuilder;
+        _botRoster = botRoster;
+        _log = log;
+    }
+
+    private bool TryGetViewerId(out long viewerId)
+    {
+        viewerId = 0;
+        var claim = User.Claims.FirstOrDefault(c => c.Type == ShadowverseClaimTypes.ViewerIdClaim)?.Value;
+        return claim is not null && long.TryParse(claim, out viewerId);
+    }
+
+    [HttpPost("/rotation_rank_battle/do_matching")]
+    public Task<IActionResult> DoMatchingRotation([FromBody] DoMatchingRequestDto req, CancellationToken ct)
+        => DoMatchingInternal("rotation_rank_battle", Format.Rotation, req, ct);
+
+    [HttpPost("/unlimited_rank_battle/do_matching")]
+    public Task<IActionResult> DoMatchingUnlimited([FromBody] DoMatchingRequestDto req, CancellationToken ct)
+        => DoMatchingInternal("unlimited_rank_battle", Format.Unlimited, req, ct);
+
+    [HttpPost("/ai_rotation_rank_battle/start")]
+    public Task<IActionResult> AiStartRotation(CancellationToken ct)
+        => AiStartInternal(Format.Rotation, ct);
+
+    [HttpPost("/ai_unlimited_rank_battle/start")]
+    public Task<IActionResult> AiStartUnlimited(CancellationToken ct)
+        => AiStartInternal(Format.Unlimited, ct);
+
+    /// <summary>
+    /// Shared finish handler — RankBattleFinishTask parses the same wire shape for
+    /// all four URLs and routes server-side by URL (vs IsAINetwork flag in the client).
+    /// Stubbed for Phase 3: echo battle_result, emit zeros elsewhere. Real rank
+    /// progression math is a separate spec.
+    /// </summary>
+    [HttpPost("/rotation_rank_battle/finish")]
+    [HttpPost("/unlimited_rank_battle/finish")]
+    [HttpPost("/ai_rotation_rank_battle/finish")]
+    [HttpPost("/ai_unlimited_rank_battle/finish")]
+    public IActionResult Finish([FromBody] RankBattleFinishRequestDto req)
+    {
+        if (!TryGetViewerId(out var _)) return Unauthorized();
+        return Ok(new RankBattleFinishResponseDto
+        {
+            BattleResult = req.BattleResult,
+            // All other fields default to 0 in the DTO (ClassLevel defaults to 1).
+        });
+    }
+
+    [HttpPost("/rank_battle/force_finish")]
+    public IActionResult ForceFinish()
+    {
+        if (!TryGetViewerId(out var _)) return Unauthorized();
+        return Ok(new { });
+    }
+
+    [HttpPost("/rank_battle/add_client_log")]
+    [HttpPost("/rank_battle/add_all_client_log")]
+    [HttpPost("/rank_battle/add_last_turn_log")]
+    public IActionResult AddClientLog()
+    {
+        if (!TryGetViewerId(out var _)) return Unauthorized();
+        return Ok(new { });
+    }
+
+    [HttpPost("/rank_battle/get_latest_master_point")]
+    public IActionResult GetLatestMasterPoint()
+    {
+        if (!TryGetViewerId(out var _)) return Unauthorized();
+        return Ok(new { });
+    }
+
+    // Filled in by Task 9.
+    private Task<IActionResult> DoMatchingInternal(string mode, Format format, DoMatchingRequestDto req, CancellationToken ct)
+    {
+        if (!TryGetViewerId(out var _)) return Task.FromResult<IActionResult>(Unauthorized());
+        // Placeholder; real impl arrives in Task 9.
+        return Task.FromResult<IActionResult>(Ok(new DoMatchingResponseDto { MatchingState = 3002 }));
+    }
+
+    // Filled in by Task 10.
+    private Task<IActionResult> AiStartInternal(Format format, CancellationToken ct)
+    {
+        if (!TryGetViewerId(out var _)) return Task.FromResult<IActionResult>(Unauthorized());
+        // Placeholder; real impl arrives in Task 10.
+        return Task.FromResult<IActionResult>(Ok(new AiBattleStartResponseDto { AiId = -1 }));
+    }
+}