List installed frontend refs in admin API

docs/development/API/admin_api.md

@@ -1585,6 +1585,7 @@ Returns the content of the document
     "build_url": "https://git.pleroma.social/pleroma/fedi-fe/-/jobs/artifacts/${ref}/download?job=build",
     "git": "https://git.pleroma.social/pleroma/fedi-fe",
     "installed": true,
+    "installed_refs": ["master"],
     "name": "fedi-fe",
     "ref": "master"
   },
@@ -1592,6 +1593,7 @@ Returns the content of the document
     "build_url": "https://git.pleroma.social/lambadalambda/kenoma/-/jobs/artifacts/${ref}/download?job=build",
     "git": "https://git.pleroma.social/lambadalambda/kenoma",
     "installed": false,
+    "installed_refs": [],
     "name": "kenoma",
     "ref": "master"
   }

lib/pleroma/web/admin_api/controllers/frontend_controller.ex

@@ -22,7 +22,9 @@ def index(conn, _params) do
       [:frontends, :available]
       |> Config.get([])
       |> Enum.map(fn {name, desc} ->
-        Map.put(desc, "installed", name in installed)
+        desc
+        |> Map.put("installed", name in installed)
+        |> Map.put("installed_refs", installed_refs(name))
       end)
 
     render(conn, "index.json", frontends: frontends)
@@ -43,4 +45,12 @@ defp installed do
       []
     end
   end
+
+  def installed_refs(name) do
+    if name in installed() do
+      File.ls!(Path.join(Pleroma.Frontend.dir(), name))
+    else
+      []
+    end
+  end
 end

lib/pleroma/web/admin_api/views/frontend_view.ex

@@ -15,7 +15,8 @@ def render("show.json", %{frontend: frontend}) do
       git: frontend["git"],
       build_url: frontend["build_url"],
       ref: frontend["ref"],
-      installed: frontend["installed"]
+      installed: frontend["installed"],
+      installed_refs: frontend["installed_refs"]
     }
   end
 end

lib/pleroma/web/api_spec/operations/admin/frontend_operation.ex

@@ -52,7 +52,8 @@ defp list_of_frontends do
           git: %Schema{type: :string, format: :uri, nullable: true},
           build_url: %Schema{type: :string, format: :uri, nullable: true},
           ref: %Schema{type: :string},
-          installed: %Schema{type: :boolean}
+          installed: %Schema{type: :boolean},
+          installed_refs: %Schema{type: :array, items: %Schema{type: :string}}
         }
       }
     }