Refactor project structure and update documentation. Replace PixiJS with plain DOM for UI rendering, enhance README with game features, and revise protocol documentation for HTTP API. Remove unused files and streamline client code for better maintainability.

src/HSchool.Server/Program.cs

@@ -1,4 +1,5 @@
 using System.Net.WebSockets;
+using HSchool.Server.Api;
 using HSchool.Server.Game;
 using HSchool.Server.Net;
 using HSchool.Simulation;
@@ -13,7 +14,9 @@ builder.Services
     .AddOptions<SimulationOptions>()
     .Bind(builder.Configuration.GetSection(SimulationOptions.SectionName))
     .Validate(options => options.TickRate is > 0 and <= 120, "Simulation:TickRate must be between 1 and 120.")
-    .Validate(options => options.WorldWidth > 0 && options.WorldHeight > 0, "World size must be positive.")
+    .Validate(options => options.MaxSchools is > 0 and <= 255, "Simulation:MaxSchools must be between 1 and 255.")
+    .Validate(options => options.GameMinutesPerRealSecond > 0, "Simulation:GameMinutesPerRealSecond must be positive.")
+    .Validate(options => GameClock.IsValidStartDate(options.DefaultStartDate), "Simulation:DefaultStartDate is out of range.")
     .ValidateOnStart();
 
 builder.Services.AddSingleton<GameCommandQueue>();
@@ -39,18 +42,12 @@ app.UseWebSockets(new WebSocketOptions
     KeepAliveInterval = TimeSpan.FromSeconds(30),
 });
 
-var api = app.MapGroup("/api");
+app.MapSchoolEndpoints();
 
-api.MapGet("/status", (GameLoopService loop, ClientRegistry clients) =>
+app.MapGet("/api/status", (GameLoopService loop, ClientRegistry clients) =>
 {
-    var options = loop.Options;
-    return new GameStatusResponse(
-        loop.CurrentTick,
-        options.TickRate,
-        loop.PlayerCount,
-        clients.Count,
-        options.WorldWidth,
-        options.WorldHeight);
+    var state = loop.SchoolsState;
+    return new GameStatusResponse(loop.CurrentTick, loop.Options.TickRate, state.Schools.Count, state.MaxSchools, clients.Count);
 })
 .WithName("GetGameStatus");
 
@@ -75,14 +72,8 @@ app.UseFileServer();
 
 app.Run();
 
-/// <summary>Snapshot of loop health for dashboards and integration tests.</summary>
-internal sealed record GameStatusResponse(
-    uint Tick,
-    int TickRate,
-    int Players,
-    int Connections,
-    float WorldWidth,
-    float WorldHeight);
+/// <summary>Loop health for dashboards and integration tests.</summary>
+internal sealed record GameStatusResponse(uint Tick, int TickRate, int Schools, int MaxSchools, int Connections);
 
 /// <summary>Exposed so <c>WebApplicationFactory</c>-style tests can reference the entry point.</summary>
 public partial class Program;