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.Tests/Federation/QuoteTests.cs

@@ -139,15 +139,15 @@ namespace PrivaPub.Tests.Federation
 		}
 
 		[Fact]
-		public async Task A_legacy_post_is_quoted_without_asking_and_another_persona_cannot_be_quoted_yet()
+		public async Task A_legacy_post_is_quoted_without_asking_and_a_persona_that_allows_nobody_cannot_be_quoted()
 		{
 			var token = TestContext.Current.CancellationToken;
 			var (aliceRoot, alice) = await _harness.Persona("alice");
 			var (bobRoot, bob) = await _harness.Persona("bob");
 			var kitty = new RemoteActor(_harness.Peer, "kitty");
 			var legacy = await Delivered(kitty, alice.Uri);
-			await _harness.Posts.InsertPost(bobRoot, new InsertPostForm { AvatarId = bob.Id, Text = "mine" }, token);
-			var bobs = await DB.Default.Find<Post>().Match(p => p.GroupUserId == bob.Id).ExecuteFirstAsync(token);
+			bob.Settings.QuotePolicy = PrivaPub.Models.User.QuotePolicies.Nobody;
+			var bobs = (await _harness.Statuses.Publish(bob, new StatusDraft { Text = "mine" }, token)).Post;
 
 			var outcome = await _harness.Statuses.Publish(alice, new StatusDraft { Text = "nice", QuotedStatusId = legacy.ID }, token);
 			Assert.Equal(QuoteState.Accepted, outcome.Post.QuoteState);
@@ -155,5 +155,67 @@ namespace PrivaPub.Tests.Federation
 			Assert.False((await _harness.Statuses.Publish(alice, new StatusDraft { Text = "and this", QuotedStatusId = bobs.ID }, token)).Ok);
 			Assert.True((await _harness.Statuses.Publish(bob, new StatusDraft { Text = "me again", QuotedStatusId = bobs.ID }, token)).Ok);
 		}
+
+		JsonObject Request(RemoteActor quoter, string quotedUri, string quotingId) => new()
+		{
+			["id"] = NewId(quoter, "activities"), ["type"] = "QuoteRequest", ["actor"] = quoter.Id, ["object"] = quotedUri,
+			["instrument"] = new JsonObject { ["id"] = quotingId, ["type"] = "Note", ["attributedTo"] = quoter.Id, ["quote"] = quotedUri, ["content"] = "<p>so true</p>" }
+		};
+
+		[Fact]
+		public async Task Anyone_may_quote_a_persona_by_default_and_the_licence_can_be_revoked()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var mallory = new RemoteActor(_harness.Peer, "mallory");
+			await _harness.Deliver(mallory, "/human-centipede", new JsonObject { ["id"] = NewId(mallory, "follows"), ["type"] = "Follow", ["actor"] = mallory.Id, ["object"] = alice.Uri });
+			var original = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "quote me" }, token)).Post;
+			var created = (await _harness.Outgoing(mallory.Id + "/inbox")).Single(a => a["type"]!.GetValue<string>() == "Create")["object"]!;
+			Assert.Equal(Addressing.Public, created["interactionPolicy"]!["canQuote"]!["automaticApproval"]![0]!.GetValue<string>());
+
+			var quotingId = NewId(mallory, "notes");
+			await _harness.Deliver(mallory, "/human-centipede", Request(mallory, original.ObjectURI, quotingId));
+			var accept = Assert.Single(await _harness.Outgoing(mallory.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Accept" && a["result"] != null);
+			var licence = accept["result"]!.GetValue<string>();
+			Assert.StartsWith(alice.Uri + "/parrot-licences/", licence);
+
+			var quoting = await Delivered(mallory, alice.Uri, n => { n["id"] = quotingId; n["quote"] = original.ObjectURI; n["quoteAuthorization"] = licence; });
+			Assert.Equal(QuoteState.Accepted, quoting.QuoteState);
+			Assert.Equal(1, (await DB.Default.Find<Post>().OneAsync(original.ID, token)).QuotesCount);
+
+			Assert.True(await _harness.Quotes.RevokeLicence(original, quoting, token));
+			Assert.Equal(QuoteState.Revoked, (await DB.Default.Find<Post>().OneAsync(quoting.ID, token)).QuoteState);
+			Assert.Contains(await _harness.Outgoing(mallory.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Delete" && a["object"]!.GetValue<string>() == licence);
+		}
+
+		[Fact]
+		public async Task A_followers_only_persona_turns_a_stranger_down()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			alice.Settings.QuotePolicy = PrivaPub.Models.User.QuotePolicies.Followers;
+			var original = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "friends only quoting" }, token)).Post;
+			var stranger = new RemoteActor(_harness.Peer, "stranger");
+
+			await _harness.Deliver(stranger, "/human-centipede", Request(stranger, original.ObjectURI, NewId(stranger, "notes")));
+
+			Assert.Equal("Reject", Assert.Single(await _harness.Outgoing(stranger.Id + "/inbox"))["type"]!.GetValue<string>());
+		}
+
+		[Fact]
+		public async Task One_persona_quotes_another_with_a_licence()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var (_, alice) = await _harness.Persona("alice");
+			var (_, bob) = await _harness.Persona("bob");
+			var original = (await _harness.Statuses.Publish(alice, new StatusDraft { Text = "public thought" }, token)).Post;
+
+			var outcome = await _harness.Statuses.Publish(bob, new StatusDraft { Text = "agreed", QuotedStatusId = original.ID }, token);
+
+			Assert.True(outcome.Ok);
+			Assert.Equal(QuoteState.Accepted, outcome.Post.QuoteState);
+			Assert.StartsWith(alice.Uri + "/parrot-licences/", outcome.Post.QuoteAuthorizationURI);
+			Assert.Equal(1, (await DB.Default.Find<Post>().OneAsync(original.ID, token)).QuotesCount);
+		}
 	}
 }