test: move application tests to tests/

test_support/test_helpers -> tests/support; watched_at unified w/ domain test_watched_at (2024-03-15).
Kept inline: users::diary_filter tests (feed_sort_to_direction_all_variants, paged_user_filter_builds_correctly) - pub(super) helpers in private module.
Dropped stale never-compiled users/tests/get_users.rs (old execute signature).

crates/application/tests/movies/get_movies_test.rs

@@ -0,0 +1,24 @@
+use domain::testing::InMemoryStore;
+
+use application::movies::{deps::GetMoviesDeps, get_movies, queries::GetMoviesQuery};
+
+#[tokio::test]
+async fn returns_empty_when_no_movies() {
+    let movie = InMemoryStore::new();
+    let deps = GetMoviesDeps { movie };
+
+    let result = get_movies::execute(
+        &deps,
+        GetMoviesQuery {
+            limit: None,
+            offset: None,
+            search: None,
+            genre: None,
+            language: None,
+        },
+    )
+    .await
+    .unwrap();
+
+    assert!(result.items.is_empty());
+}