P6 done: personas can be quoted, under the owner's default of anyone, automatically

- Our public and unlisted posts state interactionPolicy.canQuote. The policy comes from the post, then the persona
  (`source[quote_policy]`: public, followers or nobody; default public as the owner chose), and is always nobody for
  followers-only posts and DMs.
- QuoteRequests are answered with Accept{result} naming a parrot-licence at /peasants/{name}/parrot-licences/{id}
  (the route name the owner chose), or with Reject. Followers-only checks that the requester really follows.
- A licence is a QuoteAuthorization naming both posts; revoking it (POST /api/v1/statuses/:id/quotes/:quoting_id/revoke)
  marks it 410, sends Delete{licence} to the quoter and the persona's followers, and revokes our own copy of the quote.
- A quote that arrives with one of our licences is accepted only if that licence is ours, unrevoked and names exactly
  that quoting post. One persona quoting another gets a licence too.
- Mastodon API: quote_approval for our posts (automatic, followers, current_user), `quote_approval_policy` when posting,
  PUT /api/v1/statuses/:id/interaction_policy, `source.quote_policy`.

Checked live: GoToSocial still accepts our posts with the policy stated, and leaves likes, replies and boosts open.

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

PrivaPub/Models/Federation/QuoteLicence.cs

@@ -0,0 +1,14 @@
+using MongoDB.Entities;
+
+namespace PrivaPub.Models.Federation
+{
+	public class QuoteLicence : Entity
+	{
+		public string PostId { get; set; }//the quoted local post
+		public string AuthorAvatarId { get; set; }
+		public string QuotingObjectURI { get; set; }
+		public string QuoterActorURI { get; set; }
+		public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+		public DateTime? RevokedAt { get; set; }
+	}
+}

PrivaPub/Models/Post/Post.cs

@@ -60,7 +60,8 @@ namespace PrivaPub.Models.Post
 		public string QuotedPostId { get; set; }//our copy of the quoted post, once fetched
 		public QuoteState QuoteState { get; set; }
 		public string QuoteAuthorizationURI { get; set; }//FEP-044f: the quoted author's stamp
-		public bool QuoteByConsent { get; set; }//our quote of a post whose server asks for consent (FEP-044f), so `quote` is sent
+		public bool QuoteByConsent { get; set; }
+		public string LocalQuotePolicy { get; set; }//who may quote this local post: QuotePolicies.Public, Followers or Nobody//our quote of a post whose server asks for consent (FEP-044f), so `quote` is sent
 		public int QuotesCount { get; set; }
 		[BsonIgnoreIfNull]
 		public InteractionRule QuotePolicy { get; set; }//a remote post's interactionPolicy.canQuote; null when it states none

PrivaPub/Models/User/Avatar.cs

@@ -110,6 +110,16 @@ namespace PrivaPub.Models.User
 		public string DefaultVisibility { get; set; } = "public";
 		public bool DefaultSensitive { get; set; }
 		public string DefaultLanguage { get; set; }
+		public string QuotePolicy { get; set; } = QuotePolicies.Public;//owner decision: anyone may quote a public post, automatically
+	}
+
+	public static class QuotePolicies
+	{
+		public const string Public = "public";
+		public const string Followers = "followers";
+		public const string Nobody = "nobody";
+
+		public static bool IsKnown(string value) => value is Public or Followers or Nobody;
 	}
 
 	public enum AvatarServer