Outbound documents speak Mastodon's dialect under PrivaPub's route names

Local text (Domain/Content/ContentRenderer): Markdig with raw HTML off and
autolinks, or plain text for API clients; then @user and @user@host are
resolved (locally or through WebFinger) into Mastodon's h-card markup and
#tags into hashtag links, skipping code, links and e-mail addresses. A
post stores the result, its mentions and its tags, and is delivered to
the mentioned actors and the parent's author as well as to followers.

Renderer:
- Mastodon's @context (toot, schema PropertyValue, discoverable,
  indexable, blurhash, focalPoint, featured, alsoKnownAs, movedTo) and
  FEP-2c59's webfinger;
- an actor's url is its HTML page, its fields are PropertyValue
  attachments, published is cut to the day and indexable is false;
- a note's content is the stored rendering; a title becomes name and a
  bold first line, a content warning without its own text is summarised
  by the title or "Content warning"; Mention and Hashtag tags, contentMap,
  updated, and to/cc by visibility.

Routes take the agreed names: /groupies, /stalking, /scribbles/{id},
/grunts/{id} (a Create resolves), /whispers/{id} for a DM's context. The
outbox is a collection with a first page, paged by max_id. A browser
asking for an actor or a note is redirected to /@user, and WebFinger's
profile-page points there.

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

PrivaPub/Middleware/SocialPubConfigurations.cs

@@ -15,6 +15,7 @@ using PrivaPub.Federation.Actors;
 using PrivaPub.Federation.Outbox;
 using PrivaPub.Federation.Inbox;
 using PrivaPub.Federation.Inbox.Handlers;
+using PrivaPub.Domain.Content;
 using PrivaPub.Infrastructure.Http;
 using PrivaPub.Infrastructure.Jobs;
 using Microsoft.Extensions.Options;
@@ -49,6 +50,7 @@ namespace PrivaPub.Middleware
 					SafeHttpHandlerFactory.Create(provider.GetRequiredService<IOptions<FederationOptions>>().Value));
 			return service
 				.AddSingleton<IFederationHttp, FederationHttp>()
+				.AddSingleton<IContentRenderer, ContentRenderer>()
 				.AddSingleton<ILocalActorService, LocalActorService>()
 				.AddSingleton<IRemoteActorService, RemoteActorService>()
 				.AddSingleton<IDeliveryService, DeliveryService>()