feat: directory moves — mirrored batch relocation of every indexed file under a dir

- MovePlan gains moves[] (file move = 1 relocation), left_behind[] for
  unindexable files that deliberately stay, prune_dirs[] applied after the
  batch (remove_dir only succeeds when empty, leftovers keep their home)
- plan::dir: nesting/target-exists guards, merged per-file rewrites
- apply: atomic N-rename batch (per-file git mv), rollback restores every
  move, rewrite and created dir newest-first
- mv_reject accepts dirs; --json adds moved_files/would_move_files only for
  real dir moves (single-file contract byte-identical); summary shows
  (N files) and left-behind count
- engine rollback/prune tests moved to tests/apply.rs (public API; a
  mid-batch failure cannot be forced through the CLI), java-rule e2e split
  into its own binary to keep every file under the 250-line budget

todo.md

@@ -91,7 +91,7 @@ AI оставляем СНАРУЖИ: при неоднозначности jmov
 - [ ] Поддержка tsconfig paths / алиасов (@/...)
 - [ ] Параллельная индексация через rayon
 - [x] --git интеграция (git mv для stage/истории): auto для tracked файлов, --no-git флаг, moved_via/would_move_via в --json
-- [ ] Перенос директорий целиком (mv папки)
+- [x] Перенос директорий целиком (mv папки): зеркальный batch-move всех индексируемых файлов, merged rewrites, prune пустых исходных каталогов, left_behind для неиндексируемых
 - [ ] Предупреждения о не-import ссылках: package.json exports, jest mocks, tsconfig includes, markdown links
 - [ ] prettier интеграция после rewrite (по желанию)