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/client.py

@@ -111,6 +111,39 @@ def _format_redmine_error(exc: Exception) -> str:
     return str(exc)
 
 
+def _load_time_entry_activities(redmine: Redmine) -> Dict[int, str]:
+    """Загружает справочник типов активности time entries.
+
+    Возвращает словарь id -> name. Если справочник недоступен,
+    возвращает пустой словарь — тогда будем использовать данные из самих entries.
+    """
+    try:
+        activities = redmine.enumeration.filter(resource="time_entry_activities")
+        return {int(a.id): str(a.name) for a in activities}
+    except Exception:
+        return {}
+
+
+def _get_activity_name(entry, activities: Dict[int, str]) -> str:
+    """Определяет название активности для time entry."""
+    activity = getattr(entry, "activity", None)
+    if activity is None:
+        return "<N/A>"
+
+    # activity может быть объектом с id/name или просто значением
+    activity_id = getattr(activity, "id", None)
+    if activity_id is not None:
+        name = activities.get(int(activity_id))
+        if name:
+            return name
+        activity_name = getattr(activity, "name", None)
+        if activity_name:
+            return str(activity_name)
+        return str(activity_id)
+
+    return str(activity)
+
+
 def _fetch_issues_chunked(redmine: Redmine, issue_ids: List[int]) -> List[Issue]:
     """Загружает задачи чанками, чтобы не превышать лимит длины URL (#21)."""
     all_issues: List[Issue] = []
@@ -186,12 +219,14 @@ def fetch_issues_with_spent_time(
     from_date: str,
     to_date: str,
     user_id: Optional[Union[int, str]] = None,
-) -> Optional[List[Tuple[Issue, float]]]:
+    by_activity: bool = False,
+) -> Optional[List[Tuple[Issue, float, Optional[Dict[str, float]]]]]:
     """
     Fetch unique issues linked to time entries of the given user in date range,
     along with total spent hours per issue.
     If user_id is None, uses current user.
-    Returns list of (issue, total_hours) tuples.
+    If by_activity is True, returns per-activity breakdown as third tuple element.
+    Returns list of (issue, total_hours, activities) tuples.
     Raises RedmineAPIError on API/auth/network failures.
     """
 
@@ -202,6 +237,7 @@ def fetch_issues_with_spent_time(
             if user_id is not None
             else _get_current_user_id(redmine)
         )
+        activities_lookup = _load_time_entry_activities(redmine) if by_activity else {}
         time_entries = redmine.time_entry.filter(
             user_id=target_user_id, from_date=from_date, to_date=to_date
         )
@@ -210,14 +246,21 @@ def fetch_issues_with_spent_time(
     except Exception as exc:
         raise RedmineAPIError(_format_redmine_error(exc), original=exc) from exc
 
-    # Агрегируем часы по issue.id
+    # Агрегируем часы по issue.id (и активности, если требуется)
     spent_time: Dict[int, float] = {}
+    spent_by_activity: Dict[int, Dict[str, float]] = {}
     issue_ids = set()
     for entry in time_entries:
         if hasattr(entry, "issue") and entry.issue and hasattr(entry, "hours"):
             iid = entry.issue.id
+            hours = float(entry.hours)
             issue_ids.add(iid)
-            spent_time[iid] = spent_time.get(iid, 0.0) + float(entry.hours)
+            spent_time[iid] = spent_time.get(iid, 0.0) + hours
+
+            if by_activity:
+                activity_name = _get_activity_name(entry, activities_lookup)
+                by_act = spent_by_activity.setdefault(iid, {})
+                by_act[activity_name] = by_act.get(activity_name, 0.0) + hours
 
     if not issue_ids:
         return None
@@ -234,7 +277,9 @@ def fetch_issues_with_spent_time(
     # здесь оставляем порядок API как есть.
     result = []
     for issue in issues:
-        total_hours = spent_time.get(issue.id, 0.0)
-        result.append((issue, total_hours))
+        iid = issue.id
+        total_hours = spent_time.get(iid, 0.0)
+        activity_breakdown = spent_by_activity.get(iid) if by_activity else None
+        result.append((issue, total_hours, activity_breakdown))
 
     return result