Move the federation code under Federation/, namespaces only

Services/Federation and Controllers/ServerToServer become
Federation/{Actors,Signing,Inbox,Outbox,Rendering,Controllers}, the first step
of the roadmap's layout. No type, route or behaviour changes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

PrivaPub/Federation/Controllers/WellKnownController.cs

@@ -0,0 +1,96 @@
+using Microsoft.AspNetCore.Mvc;
+
+using MongoDB.Entities;
+
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.User;
+using PrivaPub.StaticServices;
+
+using System.Text.Json.Nodes;
+
+using PostEntity = PrivaPub.Models.Post.Post;
+using PrivaPub.Federation.Actors;
+
+namespace PrivaPub.Federation.Controllers
+{
+	[ApiController]
+	public class WellKnownController : ControllerBase
+	{
+		readonly ILocalActorService _localActors;
+		readonly DbEntities _dbEntities;
+
+		public WellKnownController(ILocalActorService localActors, DbEntities dbEntities)
+		{
+			_localActors = localActors;
+			_dbEntities = dbEntities;
+		}
+
+		[HttpGet, Route("/.well-known/webfinger")]
+		public async Task<IActionResult> WebFinger([FromQuery] string resource, CancellationToken token)
+		{
+			if (string.IsNullOrEmpty(resource))
+				return BadRequest();
+
+			LocalActor actor;
+			if (resource.StartsWith("acct:", StringComparison.OrdinalIgnoreCase))
+			{
+				var parts = resource[5..].TrimStart('@').Split('@');
+				var domain = new Uri(_localActors.BaseAddress).Authority;
+				if (parts.Length != 2 || !parts[1].Equals(domain, StringComparison.OrdinalIgnoreCase))
+					return NotFound();
+				actor = await _localActors.FindByUserName(parts[0], token);
+			}
+			else
+				actor = await _localActors.FindByUri(resource, token);
+
+			if (actor == default)
+				return NotFound();
+
+			var document = new JsonObject
+			{
+				["subject"] = $"acct:{actor.Handle}",
+				["aliases"] = new JsonArray(actor.Uri),
+				["links"] = new JsonArray(
+					new JsonObject { ["rel"] = "self", ["type"] = "application/activity+json", ["href"] = actor.Uri },
+					new JsonObject { ["rel"] = "http://webfinger.net/rel/profile-page", ["type"] = "text/html", ["href"] = actor.Uri })
+			};
+			return Content(document.ToJsonString(), "application/jrd+json; charset=utf-8");
+		}
+
+		[HttpGet, Route("/.well-known/nodeinfo")]
+		public IActionResult NodeInfoLinks()
+		{
+			var document = new JsonObject
+			{
+				["links"] = new JsonArray(new JsonObject
+				{
+					["rel"] = "http://nodeinfo.diaspora.software/ns/schema/2.0",
+					["href"] = $"{_localActors.BaseAddress}/nodeinfo/2.0"
+				})
+			};
+			return Content(document.ToJsonString(), "application/json; charset=utf-8");
+		}
+
+		[HttpGet, Route("/nodeinfo/2.0")]
+		public async Task<IActionResult> NodeInfo(CancellationToken token)
+		{
+			var users = await DB.Default.CountAsync<Avatar>(a => !a.DeletionAt.HasValue, token);
+			var posts = await DB.Default.CountAsync<PostEntity>(p => !p.IsFederatedCopy, token);
+			var document = new JsonObject
+			{
+				["version"] = "2.0",
+				["software"] = new JsonObject { ["name"] = "privapub", ["version"] = BuildInfo.Ref },
+				["protocols"] = new JsonArray("activitypub"),
+				["services"] = new JsonObject { ["inbound"] = new JsonArray(), ["outbound"] = new JsonArray() },
+				["openRegistrations"] = true,
+				["usage"] = new JsonObject
+				{
+					["users"] = new JsonObject { ["total"] = users },
+					["localPosts"] = posts
+				},
+				["metadata"] = new JsonObject()
+			};
+			return Content(document.ToJsonString(), "application/json; profile=\"http://nodeinfo.diaspora.software/ns/schema/2.0#\"; charset=utf-8");
+		}
+	}
+}