feat(xlsx): make Excel export production-grade

- Add merge cells for project/version groups.
- Add numeric Hours column and human-readable Spent Time.
- Add version/project/grand totals.
- Apply auto-width, freeze panes, auto-filter and styling.
- Respect --no-time: keep columns empty, skip totals.
- Pass no_time flag through formatter factory to all file formatters.
- Add tests for XLSX features and --no-time behavior.

Closes #38

tests/test_cli.py

@@ -208,3 +208,20 @@ def test_total_issues_message_goes_to_stderr(mock_fetch, capsys):
     captured = capsys.readouterr()
     assert "Total issues" not in captured.out
     assert "Total issues" in captured.err
+
+
+@mock.patch.dict(os.environ, VALID_ENV, clear=True)
+@mock.patch("redmine_reporter.cli.fetch_issues_with_spent_time")
+def test_cli_no_time_passed_to_formatter(mock_fetch, tmp_path):
+    """CLI --no-time передаётся в файловый форматтер."""
+    issue = _MockIssue()
+    mock_fetch.return_value = [(issue, 1.0)]
+
+    output = str(tmp_path / "report.xlsx")
+    with mock.patch("redmine_reporter.cli.get_formatter_by_extension") as mock_get_formatter:
+        mock_formatter = mock.MagicMock()
+        mock_get_formatter.return_value = mock_formatter
+        main(["--date", "2026-01-01--2026-01-31", "--output", output, "--no-time"])
+
+    _, kwargs = mock_get_formatter.call_args
+    assert kwargs.get("no_time") is True