implement media serving

AobaCore/Extensions.cs

@@ -1,6 +1,8 @@
 global using MaybeError;
 using Microsoft.Extensions.DependencyInjection;
 
+using MongoDB.Driver;
+
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -12,7 +14,13 @@ public static class Extensions
 {
 	public static IServiceCollection AddAoba(this IServiceCollection services)
 	{
+		var dbClient = new MongoClient("mongodb://NinoIna:27017");
+		var db = dbClient.GetDatabase("Aoba");
+
+		services.AddSingleton(dbClient);
+		services.AddSingleton<IMongoDatabase>(db);
 		services.AddSingleton<AobaService>();
+		services.AddSingleton<MediaService>();
 		return services;
 	}
 }