Fix 9 bugs: ODT covered-cells, CSV BOM, HTML charset, stderr, dead code

- #13 (critical): Add CoveredTableCell elements to ODT for valid row spans (ODF 1.2)
- #28: Move "Total issues" info message from stdout to stderr (clean pipe output)
- #27: Wrap HTML export in full document with DOCTYPE and meta charset utf-8
- #26: Save CSV with utf-8-sig encoding (UTF-8 BOM for Excel compatibility)
- #31: Document CSV uses full project/version values (not display_* like console/MD)
- #30: Fix ODT header formatting when author is empty (no leading dot/space)
- #36: Remove test_cli_smoke_empty testing unreachable code path (return [])
- #37: Remove unused mock_path variable in ODT test fixture
- #34: Remove unreachable len(parts) != 2 check in parse_date_range

Closes #13, #28, #27, #26, #31, #30, #36, #37, #34

redmine_reporter/formatters/odt.py

@@ -3,7 +3,7 @@ from typing import List
 
 from odf.opendocument import OpenDocument, load
 from odf.style import Style, TableCellProperties, TableColumnProperties
-from odf.table import Table, TableCell, TableColumn, TableRow
+from odf.table import CoveredTableCell, Table, TableCell, TableColumn, TableRow
 from odf.text import P
 
 from ..report_builder import group_rows_by_project_and_version
@@ -35,7 +35,10 @@ class ODTFormatter(Formatter):
 
         # Заголовок
         month_name = get_month_name_from_range(self.from_date, self.to_date)
-        header_text = f"{self.author}. Отчет за месяц {month_name}."
+        if self.author:
+            header_text = f"{self.author}. Отчет за месяц {month_name}."
+        else:
+            header_text = f"Отчет за месяц {month_name}."
         doc.text.addElement(P(stylename=para_style_name, text=header_text))
         doc.text.addElement(P(stylename=para_style_name, text=""))
 
@@ -86,15 +89,19 @@ class ODTFormatter(Formatter):
                 for r in rows_for_version:
                     row = TableRow()
 
-                    # Ячейка "Проект" - только в первой строке всего проекта
+                    # Ячейка "Проект" - только в первой строке всего проекта,
+                    # в остальных — covered-cell для валидности ODF (#13)
                     if first_version_in_project and first_row_in_version:
                         cell_project = TableCell(stylename=cell_style_name)
                         cell_project.setAttribute("numberrowsspanned", str(total_project_rows))
                         p = P(stylename=para_style_name, text=project)
                         cell_project.addElement(p)
                         row.addElement(cell_project)
+                    else:
+                        row.addElement(CoveredTableCell())
 
-                    # Ячейка "Версия" - только в первой строке каждой версии
+                    # Ячейка "Версия" - только в первой строке каждой версии,
+                    # в остальных — covered-cell для валидности ODF (#13)
                     if first_row_in_version:
                         cell_version = TableCell(stylename=cell_style_name)
                         cell_version.setAttribute("numberrowsspanned", str(row_span_version))
@@ -102,6 +109,8 @@ class ODTFormatter(Formatter):
                         cell_version.addElement(p)
                         row.addElement(cell_version)
                         first_row_in_version = False
+                    else:
+                        row.addElement(CoveredTableCell())
 
                     # Остальные колонки
                     task_cell = TableCell(stylename=cell_style_name)