Added Serilog logging, added Elmah error logging, added health checks

src/Indexer/Program.cs

@@ -1,6 +1,11 @@
+using Indexer;
 using Indexer.Models;
 using Indexer.Services;
+using ElmahCore;
+using ElmahCore.Mvc;
 using Server;
+using ElmahCore.Mvc.Logger;
+using Serilog;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -10,16 +15,32 @@ builder.Services.AddControllers();
 // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
+Log.Logger = new LoggerConfiguration()
+    .WriteTo.File("logs/log-.txt", rollingInterval: RollingInterval.Day)  // Output files with daily rolling
+    .CreateLogger();
+builder.Logging.AddSerilog();
+builder.Services.AddHttpContextAccessor();
 builder.Services.AddSingleton<Client.Client>();
 builder.Services.AddSingleton<WorkerCollection>();
 builder.Services.AddHostedService<IndexerService>();
+builder.Services.AddHealthChecks()
+    .AddCheck<WorkerHealthCheck>("WorkerHealthCheck");
+
+builder.Services.AddElmah<XmlFileErrorLog>(Options =>
+{
+    Options.LogPath = "~/logs";
+});
+
 var app = builder.Build();
+app.UseElmah();
+app.MapHealthChecks("/healthz");
 
 // Configure the HTTP request pipeline.
 if (app.Environment.IsDevelopment())
 {
     app.UseSwagger();
     app.UseSwaggerUI();
+    app.UseElmahExceptionPage();
 }
 else
 {