feat(bot): Коммит — навигация по дереву репозитория загрузок

- UploadsRepo: локальный клон, fetch не чаще fetch_interval, ls-tree -z (пробелы/кириллица),
  cat-file, последний коммит по пути; git без shell, ssh с -F /dev/null (без конфига хоста)
- «📝 Коммит»: папки/файлы с размерами, ⬆️ Вверх, страницы по 20, карточка файла
  с последним коммитом, «👁 Показать» (<pre> или документом); в кнопках только индексы
- ключ для контейнера: GIT_SSH_KEY_B64 → временный файл 0600 (смонтированный файл хоста
  контейнерному uid не прочитать); volume /data для клона
- тесты на настоящем bare-репозитории во временной папке

Refs #8

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/repo/test_git.py

@@ -0,0 +1,85 @@
+from pathlib import Path
+
+import pytest
+
+from app.repo.git import GitError, UploadsRepo
+from tests.conftest import git
+
+
+async def test_clone_and_list_root_dirs_first(repo: UploadsRepo) -> None:
+    await repo.refresh()
+
+    entries = await repo.list_dir()
+    assert [(e.name, e.kind) for e in entries] == [
+        ("docs", "dir"),
+        ("many", "dir"),
+        ("services", "dir"),
+        ("README.md", "file"),
+    ]
+    assert entries[-1].size == len("# uploads\n")
+
+
+async def test_unicode_and_spaces_in_names(repo: UploadsRepo) -> None:
+    await repo.refresh()
+
+    names = [e.path for e in await repo.list_dir("docs")]
+    assert names == ["docs/logo.bin", "docs/мои заметки.md"]
+    assert (await repo.read("docs/мои заметки.md")).decode() == "привет\n"
+
+
+async def test_last_commit_per_path(repo: UploadsRepo) -> None:
+    await repo.refresh()
+
+    hello = await repo.last_commit("services/hello/main.py")
+    docs = await repo.last_commit("docs/logo.bin")
+    assert hello is not None and hello.subject == "init" and hello.author == "Тест"
+    assert docs is not None and docs.subject == "docs and many" and len(docs.sha) == 40
+
+
+async def test_missing_dir_is_an_error(repo: UploadsRepo) -> None:
+    await repo.refresh()
+    with pytest.raises(GitError, match="no such directory"):
+        await repo.list_dir("nope")
+
+
+async def test_refresh_sees_new_commits_and_respects_interval(repo: UploadsRepo, remote: Path, tmp_path: Path) -> None:
+    await repo.refresh()
+    before = await repo.head()
+
+    other = tmp_path / "other"
+    git(tmp_path, "clone", "-q", str(remote), str(other))
+    (other / "new.txt").write_text("x", encoding="utf-8")
+    git(other, "add", "-A")
+    git(other, "commit", "-q", "-m", "new")
+    git(other, "push", "-q", "origin", "main")
+
+    await repo.refresh()
+    assert await repo.head() != before
+    assert "new.txt" in [e.name for e in await repo.list_dir()]
+
+
+async def test_fetch_is_throttled(remote: Path, tmp_path: Path) -> None:
+    from app.config import GitSettings
+
+    throttled = UploadsRepo(GitSettings(uploads_url=str(remote), clone_dir=tmp_path / "c2", fetch_interval=3600))
+    await throttled.refresh()
+    head = await throttled.head()
+    other = tmp_path / "o2"
+    git(tmp_path, "clone", "-q", str(remote), str(other))
+    (other / "x.txt").write_text("x", encoding="utf-8")
+    git(other, "add", "-A")
+    git(other, "commit", "-q", "-m", "x")
+    git(other, "push", "-q", "origin", "main")
+
+    await throttled.refresh()
+    assert await throttled.head() == head  # within the interval: no fetch
+    await throttled.refresh(force=True)
+    assert await throttled.head() != head
+
+
+async def test_unreachable_remote(tmp_path: Path) -> None:
+    from app.config import GitSettings
+
+    broken = UploadsRepo(GitSettings(uploads_url=str(tmp_path / "missing.git"), clone_dir=tmp_path / "c3"))
+    with pytest.raises(GitError, match="clone"):
+        await broken.refresh()