Fix CI: remove unused aliases, run mix format, install root yarn deps

- Remove unused aliases that caused warnings-as-errors in EX_CHECK mode
- Run mix format to fix formatter check
- Add root-level yarn install to CI for prettier (used by mix check)
- All 1007 tests pass, zero warnings

test/pinchflat_web/api_auth_plug_test.exs

@@ -62,4 +62,4 @@ defmodule PinchflatWeb.ApiAuthPlugTest do
       assert %{status: 200} = conn
     end
   end
-end
+end

test/pinchflat_web/controllers/api/v1/api_media_item_controller_test.exs

@@ -77,4 +77,4 @@ defmodule PinchflatWeb.Api.V1.ApiMediaItemControllerTest do
       assert [_] = all_enqueued(worker: MediaDownloadWorker)
     end
   end
-end
+end

test/pinchflat_web/controllers/api/v1/api_media_profile_controller_test.exs

@@ -28,7 +28,10 @@ defmodule PinchflatWeb.Api.V1.ApiMediaProfileControllerTest do
 
   describe "POST /api/v1/media_profiles" do
     test "creates a media profile and returns 201", %{conn: conn} do
-      conn = post(conn, ~p"/api/v1/media_profiles", media_profile: %{name: "Test Profile", output_path_template: "{{title}}.{{ext}}"})
+      conn =
+        post(conn, ~p"/api/v1/media_profiles",
+          media_profile: %{name: "Test Profile", output_path_template: "{{title}}.{{ext}}"}
+        )
 
       assert %{status: 201} = conn
       assert json_response(conn, 201)["data"]["name"] == "Test Profile"
@@ -40,4 +43,4 @@ defmodule PinchflatWeb.Api.V1.ApiMediaProfileControllerTest do
       assert %{status: 422} = conn
     end
   end
-end
+end

test/pinchflat_web/controllers/api/v1/api_setting_controller_test.exs

@@ -42,4 +42,4 @@ defmodule PinchflatWeb.Api.V1.ApiSettingControllerTest do
       assert data["environment"] != nil
     end
   end
-end
+end

test/pinchflat_web/controllers/api/v1/api_source_controller_test.exs

@@ -184,4 +184,4 @@ defmodule PinchflatWeb.Api.V1.ApiSourceControllerTest do
        playlist_title: "some playlist name"
      })}
   end
-end
+end

test/pinchflat_web/controllers/api/v1/api_task_controller_test.exs

@@ -45,4 +45,4 @@ defmodule PinchflatWeb.Api.V1.ApiTaskControllerTest do
       assert json_response(conn, 200)["data"]["id"] == task.id
     end
   end
-end
+end