feat(api): add the Mastodon quote entity to statuses

Mastodon 4.4+ clients read quotes from a top-level quote object with
state and quoted_status; Pleroma only had pleroma.quote, so they did
not show quote posts. Quoted statuses get a shallow quote with only
quoted_status_id, as quotes are rendered one level deep.

Inspired by Akkoma 5b7209980, which can not use the shallow form because
Akkoma already had a top-level quote status.

test/pleroma/web/mastodon_api/views/status_view_test.exs

@@ -345,7 +345,8 @@ defmodule Pleroma.Web.MastodonAPI.StatusViewTest do
         bookmark_folder: nil,
         list_id: nil
       },
-      quotes_count: 0
+      quotes_count: 0,
+      quote: nil
     }
 
     assert status == expected
@@ -507,6 +508,63 @@ defmodule Pleroma.Web.MastodonAPI.StatusViewTest do
     refute status.pleroma.quote_visible
   end
 
+  describe "Mastodon quote entity" do
+    test "a quote has the quoted status, and quoted statuses only a shallow quote" do
+      post = insert(:note_activity)
+      user = insert(:user)
+
+      {:ok, quote_post} = CommonAPI.post(user, %{status: "he", quoted_status_id: post.id})
+
+      {:ok, quoted_quote_post} =
+        CommonAPI.post(user, %{status: "yo", quoted_status_id: quote_post.id})
+
+      status = StatusView.render("show.json", %{activity: quoted_quote_post})
+
+      assert %{state: "accepted", quoted_status: %{id: quoted_id} = quoted} = status.quote
+      assert quoted_id == to_string(quote_post.id)
+      assert quoted.quote == %{state: "accepted", quoted_status_id: to_string(post.id)}
+
+      assert_schema(status, "Status", Pleroma.Web.ApiSpec.spec())
+    end
+
+    test "a quote of a post the user cannot see is unauthorized" do
+      user = insert(:user)
+      private = insert(:followers_only_note_activity, user: user)
+
+      quote_private =
+        insert(:note_activity,
+          note: insert(:note, data: %{"quoteUrl" => Object.normalize(private).data["id"]})
+        )
+
+      status = StatusView.render("show.json", %{activity: quote_private})
+      assert status.quote == %{state: "unauthorized", quoted_status: nil}
+      assert_schema(status, "Status", Pleroma.Web.ApiSpec.spec())
+
+      follower = insert(:user)
+      CommonAPI.follow(user, follower)
+
+      status = StatusView.render("show.json", %{activity: quote_private, for: follower})
+      assert %{state: "accepted", quoted_status: %{id: id}} = status.quote
+      assert id == to_string(private.id)
+    end
+
+    test "a quote of a missing post is deleted" do
+      quote_missing =
+        insert(:note_activity,
+          note: insert(:note, data: %{"quoteUrl" => "https://example.com/objects/gone"})
+        )
+
+      status = StatusView.render("show.json", %{activity: quote_missing})
+      assert status.quote == %{state: "deleted", quoted_status: nil}
+    end
+
+    test "a post without a quote has no quote" do
+      status = StatusView.render("show.json", %{activity: insert(:note_activity)})
+      assert status.quote == nil
+      assert_schema(status, "Status", Pleroma.Web.ApiSpec.spec())
+    end
+  end
+
   test "repost of quote post" do
     post = insert(:note_activity)
     user = insert(:user)