Add player onboarding and tactical viewer updates

apps/backend/Auth/Simulation/AuthService.cs

@@ -7,7 +7,7 @@ public sealed class AuthService(
     RefreshTokenFactory refreshTokenFactory,
     IPasswordResetDelivery passwordResetDelivery)
 {
-    public async Task<AuthSessionResponse> RegisterAsync(RegisterRequest request, CancellationToken cancellationToken)
+    public async Task<RegisterResponse> RegisterAsync(RegisterRequest request, CancellationToken cancellationToken)
     {
         var email = NormalizeEmail(request.Email);
         ValidatePassword(request.Password);
@@ -18,7 +18,7 @@ public sealed class AuthService(
         }
 
         var user = await authRepository.CreateUserAsync(email, passwordHasher.HashPassword(request.Password), [], cancellationToken);
-        return await CreateSessionAsync(user, cancellationToken);
+        return new RegisterResponse(user.Id, user.Email, true);
     }
 
     public async Task<AuthSessionResponse> LoginAsync(LoginRequest request, CancellationToken cancellationToken)

apps/backend/Auth/Simulation/HttpContextPlayerIdentityResolver.cs

@@ -5,6 +5,8 @@ namespace SpaceGame.Api.Auth.Simulation;
 
 public sealed class HttpContextPlayerIdentityResolver(IHttpContextAccessor httpContextAccessor) : IPlayerIdentityResolver
 {
+    public const string EffectivePlayerHeaderName = "X-Act-As-Player-Id";
+
     public Guid? GetCurrentPlayerId()
     {
         var subject = httpContextAccessor.HttpContext?.User.FindFirstValue(ClaimTypes.NameIdentifier)
@@ -15,6 +17,21 @@ public sealed class HttpContextPlayerIdentityResolver(IHttpContextAccessor httpC
     public Guid GetRequiredPlayerId() =>
       GetCurrentPlayerId() ?? throw new InvalidOperationException("Authenticated player identity is required.");
 
+    public Guid? GetEffectivePlayerId()
+    {
+        var currentPlayerId = GetCurrentPlayerId();
+        if (!CanAccessGm())
+        {
+            return currentPlayerId;
+        }
+
+        var requestedIdentity = httpContextAccessor.HttpContext?.Request.Headers[EffectivePlayerHeaderName].FirstOrDefault();
+        return Guid.TryParse(requestedIdentity, out var effectivePlayerId) ? effectivePlayerId : currentPlayerId;
+    }
+
+    public Guid GetRequiredEffectivePlayerId() =>
+      GetEffectivePlayerId() ?? throw new InvalidOperationException("Authenticated player identity is required.");
+
     public bool CanAccessGm()
     {
         var user = httpContextAccessor.HttpContext?.User;

apps/backend/Auth/Simulation/IAuthRepository.cs

@@ -4,6 +4,7 @@ public interface IAuthRepository
 {
     Task<UserAccount?> FindUserByEmailAsync(string email, CancellationToken cancellationToken);
     Task<UserAccount?> FindUserByIdAsync(Guid userId, CancellationToken cancellationToken);
+    Task<IReadOnlyList<UserAccount>> ListUsersAsync(CancellationToken cancellationToken);
     Task<UserAccount> CreateUserAsync(string email, string passwordHash, IReadOnlyCollection<string> roles, CancellationToken cancellationToken);
     Task<UserAccount> UpsertUserAsync(string email, string passwordHash, IReadOnlyCollection<string> roles, CancellationToken cancellationToken);
     Task StoreRefreshTokenAsync(Guid userId, string tokenHash, DateTimeOffset expiresAtUtc, CancellationToken cancellationToken);

apps/backend/Auth/Simulation/IPlayerIdentityResolver.cs

@@ -4,5 +4,7 @@ public interface IPlayerIdentityResolver
 {
     Guid? GetCurrentPlayerId();
     Guid GetRequiredPlayerId();
+    Guid? GetEffectivePlayerId();
+    Guid GetRequiredEffectivePlayerId();
     bool CanAccessGm();
 }

apps/backend/Auth/Simulation/PostgresAuthRepository.cs

@@ -28,6 +28,23 @@ public sealed class PostgresAuthRepository(NpgsqlDataSource dataSource) : IAuthR
         return await reader.ReadAsync(cancellationToken) ? ReadUser(reader) : null;
     }
 
+    public async Task<IReadOnlyList<UserAccount>> ListUsersAsync(CancellationToken cancellationToken)
+    {
+        await using var command = dataSource.CreateCommand("""
+            select id, email, password_hash, created_at_utc, roles
+            from auth_users
+            order by email asc
+            """);
+        await using var reader = await command.ExecuteReaderAsync(cancellationToken);
+        var users = new List<UserAccount>();
+        while (await reader.ReadAsync(cancellationToken))
+        {
+            users.Add(ReadUser(reader));
+        }
+
+        return users;
+    }
+
     public async Task<UserAccount> CreateUserAsync(string email, string passwordHash, IReadOnlyCollection<string> roles, CancellationToken cancellationToken)
     {
         var userId = Guid.NewGuid();