style: primary constructors for position state types

Use C# primary constructors and camelCase private fields per csharp-style.
Refactor InMemoryPositionStateStore seeding into CreateInitialMap; align
Postgres integration tests and PositionStateApiTests with factory/httpClient
naming.

server/NeonSprawl.Server.Tests/Game/PositionState/PositionStateApiTests.cs

@@ -9,7 +9,7 @@ namespace NeonSprawl.Server.Tests.Game.PositionState;
 public class PositionStateApiTests(InMemoryWebApplicationFactory factory)
     : IClassFixture<InMemoryWebApplicationFactory>
 {
-    private readonly HttpClient _client = factory.CreateClient();
+    private readonly HttpClient httpClient = factory.CreateClient();
 
     [Fact]
     public async Task GetPosition_ShouldReturnVersionedPayloadAtOrigin_WhenDevPlayerRequested()
@@ -18,7 +18,7 @@ public class PositionStateApiTests(InMemoryWebApplicationFactory factory)
         const string url = "/game/players/dev-local-1/position";
 
         // Act
-        var response = await _client.GetAsync(url);
+        var response = await httpClient.GetAsync(url);
 
         // Assert
         Assert.Equal(HttpStatusCode.OK, response.StatusCode);
@@ -39,7 +39,7 @@ public class PositionStateApiTests(InMemoryWebApplicationFactory factory)
         const string url = "/game/players/DEV-LOCAL-1/position";
 
         // Act
-        var response = await _client.GetAsync(url);
+        var response = await httpClient.GetAsync(url);
 
         // Assert
         Assert.Equal(HttpStatusCode.OK, response.StatusCode);
@@ -57,7 +57,7 @@ public class PositionStateApiTests(InMemoryWebApplicationFactory factory)
         const string url = "/game/players/unknown-player/position";
 
         // Act
-        var response = await _client.GetAsync(url);
+        var response = await httpClient.GetAsync(url);
 
         // Assert
         Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);

server/NeonSprawl.Server.Tests/Game/PositionState/PostgresPositionStateIntegrationTests.cs

@@ -10,21 +10,14 @@ namespace NeonSprawl.Server.Tests.Game.PositionState;
 
 /// <summary>NS-17: real PostgreSQL + HTTP; collection serializes tests that share the database.</summary>
 [Collection("Postgres integration")]
-public sealed class PostgresPositionStateIntegrationTests
+public sealed class PostgresPositionStateIntegrationTests(PostgresWebApplicationFactory factory)
 {
-    private readonly PostgresWebApplicationFactory _factory;
-
-    public PostgresPositionStateIntegrationTests(PostgresWebApplicationFactory factory)
-    {
-        _factory = factory;
-    }
-
     [RequirePostgresFact]
     public async Task PostMove_ThenGet_ShouldReflectPersistedPositionAndSequence()
     {
         // Arrange
         await ResetPlayerPositionTableAsync();
-        using var client = _factory.CreateClient();
+        using var client = factory.CreateClient();
         var cmd = new MoveCommandRequest
         {
             SchemaVersion = MoveCommandRequest.CurrentSchemaVersion,
@@ -68,7 +61,7 @@ public sealed class PostgresPositionStateIntegrationTests
         PositionStateResponse? persisted = null;
 
         // Act
-        using (var first = _factory.CreateClient())
+        using (var first = factory.CreateClient())
         {
             var post = await first.PostAsJsonAsync("/game/players/dev-local-1/move", cmd);
             postStatus = post.StatusCode;
@@ -94,7 +87,7 @@ public sealed class PostgresPositionStateIntegrationTests
     {
         // Arrange
         await ResetPlayerPositionTableAsync();
-        using var client = _factory.CreateClient();
+        using var client = factory.CreateClient();
         var cmd = new MoveCommandRequest
         {
             SchemaVersion = MoveCommandRequest.CurrentSchemaVersion,
@@ -117,8 +110,8 @@ public sealed class PostgresPositionStateIntegrationTests
             throw new InvalidOperationException("ConnectionStrings__NeonSprawl is not set.");
         }
 
-        _ = _factory.Services;
+        _ = factory.Services;
-        var options = _factory.Services.GetRequiredService<IOptions<GamePositionOptions>>().Value;
+        var options = factory.Services.GetRequiredService<IOptions<GamePositionOptions>>().Value;
 
         var ddlPath = Path.Combine(AppContext.BaseDirectory, "db", "migrations", "V001__player_position.sql");
         if (!File.Exists(ddlPath))

server/NeonSprawl.Server/Game/PositionState/InMemoryPositionStateStore.cs

@@ -4,21 +4,22 @@ using Microsoft.Extensions.Options;
 namespace NeonSprawl.Server.Game.PositionState;
 
 /// <summary>Thread-safe in-memory positions; seeds the configured dev player on construction.</summary>
-public sealed class InMemoryPositionStateStore : IPositionStateStore
+public sealed class InMemoryPositionStateStore(IOptions<GamePositionOptions> options) : IPositionStateStore
 {
-    private readonly ConcurrentDictionary<string, PositionSnapshot> _positions = new(StringComparer.OrdinalIgnoreCase);
+    private readonly ConcurrentDictionary<string, PositionSnapshot> positions = CreateInitialMap(options.Value);
 
-    public InMemoryPositionStateStore(IOptions<GamePositionOptions> options)
+    private static ConcurrentDictionary<string, PositionSnapshot> CreateInitialMap(GamePositionOptions o)
     {
-        var o = options.Value;
         var id = o.DevPlayerId.Trim();
         if (id.Length == 0)
         {
             throw new InvalidOperationException("Game:DevPlayerId must be non-empty.");
         }
 
+        var map = new ConcurrentDictionary<string, PositionSnapshot>(StringComparer.OrdinalIgnoreCase);
         var p = o.DefaultPosition ?? new DefaultPositionOptions();
-        _positions[id] = new PositionSnapshot(p.X, p.Y, p.Z, 0);
+        map[id] = new PositionSnapshot(p.X, p.Y, p.Z, 0);
+        return map;
     }
 
     public bool TryGetPosition(string playerId, out PositionSnapshot snapshot)
@@ -26,11 +27,11 @@ public sealed class InMemoryPositionStateStore : IPositionStateStore
         var key = playerId?.Trim();
         if (!string.IsNullOrEmpty(key))
         {
-            return _positions.TryGetValue(key, out snapshot);
+            return positions.TryGetValue(key, out snapshot);
         }
+
         snapshot = default;
         return false;
-
     }
 
     public bool TryApplyMoveTarget(string playerId, double x, double y, double z, out PositionSnapshot snapshot)
@@ -44,17 +45,18 @@ public sealed class InMemoryPositionStateStore : IPositionStateStore
 
         while (true)
         {
-            if (!_positions.TryGetValue(key, out var previous))
+            if (!positions.TryGetValue(key, out var previous))
             {
                 snapshot = default;
                 return false;
             }
 
             var next = new PositionSnapshot(x, y, z, previous.Sequence + 1);
-            if (!_positions.TryUpdate(key, next, previous))
+            if (!positions.TryUpdate(key, next, previous))
             {
                 continue;
             }
+
             snapshot = next;
             return true;
         }

server/NeonSprawl.Server/Game/PositionState/PostgresDevPlayerSeedHostedService.cs

@@ -3,29 +3,26 @@ using Microsoft.Extensions.Options;
 namespace NeonSprawl.Server.Game.PositionState;
 
 /// <summary>Runs DDL and dev-player seed once when the host starts (PostgreSQL path only).</summary>
-internal sealed class PostgresDevPlayerSeedHostedService : IHostedService
+internal sealed class PostgresDevPlayerSeedHostedService(
+    Npgsql.NpgsqlDataSource dataSource,
+    IOptions<GamePositionOptions> positionOptions) : IHostedService
 {
-    private readonly Npgsql.NpgsqlDataSource _dataSource;
+    private readonly GamePositionOptions gameOptions = RequireDevPlayer(positionOptions.Value);
-    private readonly GamePositionOptions _options;
 
-    public PostgresDevPlayerSeedHostedService(
+    private static GamePositionOptions RequireDevPlayer(GamePositionOptions options)
-        Npgsql.NpgsqlDataSource dataSource,
-        IOptions<GamePositionOptions> options)
     {
-        _dataSource = dataSource;
+        if (string.IsNullOrWhiteSpace(options.DevPlayerId))
-        var o = options.Value;
-        if (string.IsNullOrWhiteSpace(o.DevPlayerId))
         {
             throw new InvalidOperationException("Game:DevPlayerId must be non-empty.");
         }
 
-        _options = o;
+        return options;
     }
 
     public Task StartAsync(CancellationToken cancellationToken)
     {
-        PostgresPositionBootstrap.EnsureSchema(_dataSource);
+        PostgresPositionBootstrap.EnsureSchema(dataSource);
-        PostgresPositionBootstrap.SeedDevPlayer(_dataSource, _options);
+        PostgresPositionBootstrap.SeedDevPlayer(dataSource, gameOptions);
         return Task.CompletedTask;
     }
 

server/NeonSprawl.Server/Game/PositionState/PostgresPositionStateStore.cs

@@ -3,20 +3,20 @@ using Microsoft.Extensions.Options;
 namespace NeonSprawl.Server.Game.PositionState;
 
 /// <summary>PostgreSQL-backed <see cref="IPositionStateStore"/> (NS-17). Player ids are stored normalized: invariant lower + trim for case-insensitive parity with <see cref="InMemoryPositionStateStore"/>.</summary>
-public sealed class PostgresPositionStateStore : IPositionStateStore
+public sealed class PostgresPositionStateStore(
+    Npgsql.NpgsqlDataSource dataSource,
+    IOptions<GamePositionOptions> positionOptions) : IPositionStateStore
 {
-    private readonly Npgsql.NpgsqlDataSource _dataSource;
+    private readonly GamePositionOptions gameOptions = RequireValidOptions(positionOptions.Value);
-    private readonly GamePositionOptions _options;
 
-    public PostgresPositionStateStore(Npgsql.NpgsqlDataSource dataSource, IOptions<GamePositionOptions> options)
+    private static GamePositionOptions RequireValidOptions(GamePositionOptions options)
     {
-        _dataSource = dataSource;
+        if (options.DevPlayerId.Trim().Length == 0)
-        _options = options.Value;
-        var id = _options.DevPlayerId.Trim();
-        if (id.Length == 0)
         {
             throw new InvalidOperationException("Game:DevPlayerId must be non-empty.");
         }
+
+        return options;
     }
 
     public bool TryGetPosition(string playerId, out PositionSnapshot snapshot)
@@ -28,9 +28,9 @@ public sealed class PostgresPositionStateStore : IPositionStateStore
             return false;
         }
 
-        PostgresPositionBootstrap.EnsureSchema(_dataSource);
+        PostgresPositionBootstrap.EnsureSchema(dataSource);
 
-        using var conn = _dataSource.OpenConnection();
+        using var conn = dataSource.OpenConnection();
         using var cmd = new Npgsql.NpgsqlCommand(
             "SELECT pos_x, pos_y, pos_z, sequence FROM player_position WHERE player_id = @pid;",
             conn);
@@ -55,9 +55,9 @@ public sealed class PostgresPositionStateStore : IPositionStateStore
             return false;
         }
 
-        PostgresPositionBootstrap.EnsureSchema(_dataSource);
+        PostgresPositionBootstrap.EnsureSchema(dataSource);
 
-        using var conn = _dataSource.OpenConnection();
+        using var conn = dataSource.OpenConnection();
         using var cmd = new Npgsql.NpgsqlCommand(
             """
             UPDATE player_position