feat(activity): add --by-activity flag to break down spent time by activity type

- Load time entry activity names from Redmine enumeration.
- Aggregate hours per issue and per activity in fetch_issues_with_spent_time.
- Add --by-activity CLI flag and propagate it through report builder,
  summary, and all formatters (console, CSV, HTML, JSON, ODT).
- Keep backward-compatible 2-tuple input in build_grouped_report.
- Bump version to 1.8.0.

Closes #41

redmine_reporter/formatters/console.py

@@ -12,13 +12,14 @@ class TableFormatter(Formatter):
     def format(self, rows: List[ReportRow]) -> str:
         table_rows = [["Проект", "Версия", "Задача", "Статус", "Затрачено"]]
         for r in rows:
+            time_text = r["time_text"].replace("\n", " / ")
             table_rows.append(
                 [
                     r["display_project"],
                     r["display_version"],
                     f"{r['issue_id']}. {r['subject']}",
                     r["status_ru"],
-                    r["time_text"],
+                    time_text,
                 ]
             )
         return tabulate(table_rows, headers="firstrow", tablefmt="fancy_grid")
@@ -35,9 +36,10 @@ class CompactFormatter(Formatter):
     def format(self, rows: List[ReportRow]) -> str:
         lines = []
         for r in rows:
+            time_text = r["time_text"].replace("\n", " / ")
             lines.append(
                 f"{r['display_project']} | {r['display_version']} | "
-                f"{r['issue_id']}. {r['subject']} | {r['status_ru']} | {r['time_text']}"
+                f"{r['issue_id']}. {r['subject']} | {r['status_ru']} | {time_text}"
             )
         return "\n".join(lines)