Implement per-school save functionality by introducing a dedicated save directory and updating the school management system to support loading and saving school states. Revise documentation to reflect these changes, including updates to the architecture and design documents, and enhance the API for reloading schools from disk. Update tests to ensure proper functionality of the new save and reload features.

src/HSchool.Server/Program.cs

@@ -3,6 +3,7 @@ using HSchool.Server.Api;
 using HSchool.Server.Game;
 using HSchool.Server.Net;
 using HSchool.Simulation;
+using Microsoft.Extensions.Configuration;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -17,11 +18,14 @@ builder.Services
     .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.")
+    .Validate(options => !string.IsNullOrWhiteSpace(options.SavesDirectory), "Simulation:SavesDirectory must be set.")
+    .Validate(options => options.SaveIntervalSeconds is > 0 and <= 3600, "Simulation:SaveIntervalSeconds must be between 1 and 3600.")
     .ValidateOnStart();
 
 builder.Services.AddSingleton<GameCommandQueue>();
 builder.Services.AddSingleton<ClientRegistry>();
 builder.Services.AddSingleton<GameMetrics>();
+builder.Services.AddSingleton<SchoolStore>();
 builder.Services.AddSingleton<GameSocketHandler>();
 builder.Services.AddSingleton<GameLoopService>();
 builder.Services.AddHostedService(sp => sp.GetRequiredService<GameLoopService>());
@@ -51,6 +55,16 @@ app.MapGet("/api/status", (GameLoopService loop, ClientRegistry clients) =>
 })
 .WithName("GetGameStatus");
 
+if (app.Configuration.GetValue("HSchool:AllowSaveReload", false))
+{
+    app.MapPost("/api/dev/reload-schools", async (GameLoopService loop, CancellationToken cancellationToken) =>
+    {
+        await loop.ReloadFromDiskAsync(cancellationToken);
+        return Results.NoContent();
+    })
+    .WithName("ReloadSchoolsFromDisk");
+}
+
 // The realtime channel: one binary frame per protocol message, see docs/protocol.md.
 app.Map("/ws/game", async (HttpContext context, GameSocketHandler handler) =>
 {