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

redmine_reporter/formatters/csv.py

@@ -15,24 +15,28 @@ class CSVFormatter(Formatter):
     корректного отображения кириллицы в Microsoft Excel (#26).
     """
 
-    def __init__(self, **_kwargs):
+    def __init__(self, no_time: bool = False, **_kwargs):
         super().__init__()
+        self.no_time = no_time
 
     def format(self, rows: List[ReportRow]) -> str:
         output = io.StringIO()
         writer = csv.writer(output, dialect="excel")
-        writer.writerow(["Project", "Version", "Issue ID", "Subject", "Status", "Spent Time"])
+        headers = ["Project", "Version", "Issue ID", "Subject", "Status"]
+        if not self.no_time:
+            headers.append("Spent Time")
+        writer.writerow(headers)
         for r in rows:
-            writer.writerow(
-                [
-                    r["project"],
-                    r["version"],
-                    r["issue_id"],
-                    r["subject"],
-                    r["status_ru"],
-                    r["time_text"],
-                ]
-            )
+            data = [
+                r["project"],
+                r["version"],
+                r["issue_id"],
+                r["subject"],
+                r["status_ru"],
+            ]
+            if not self.no_time:
+                data.append(r["time_text"])
+            writer.writerow(data)
         return output.getvalue()
 
     def save(self, rows: List[ReportRow], output_path: str) -> None: