feat: output path defaults (#43) + datetime precision & dedup (#47)

#43 — Имя файла и пути по умолчанию:
- resolve_output_path() в yaml_config.py: резолвит --output с учётом
  output.dir, filename_template, default_format из YAML-конфига
- Bare format (xlsx/odt/...) → путь по шаблону
- Без расширения → автодописывается default_format (.xlsx)
- Config.get_output_dir/filename/default_format()

#47 — datetime precision и дедупликация:
- period.last_used.from/to в YAML-конфиге и AppConfig
- period.precision: date|datetime
- _compute_dedup_cutoff() в cli.py: при precision=datetime вычисляет
  cutoff из period.last_used.to
- _parse_datetime() + AND-логика дедупликации в client.py:
  запись исключается если created_on И updated_on < cutoff
- Пропуск issues без часов после дедупликации

Closes #43
Closes #47

redmine_reporter/client.py

@@ -1,3 +1,4 @@
+from datetime import datetime
 from typing import Any, Dict, List, Optional, Tuple, Union
 
 import requests
@@ -144,6 +145,25 @@ def _get_activity_name(entry, activities: Dict[int, str]) -> str:
     return str(activity)
 
 
+def _parse_datetime(value: Any) -> Optional[datetime]:
+    """Parse a datetime from Redmine API response.
+
+    Accepts datetime objects, ISO strings (with or without timezone),
+    or None. Returns a timezone-aware datetime or None.
+    """
+    if value is None:
+        return None
+    if isinstance(value, datetime):
+        return value
+    if isinstance(value, str):
+        try:
+            dt = datetime.fromisoformat(value.replace("Z", "+00:00"))
+            return dt
+        except (ValueError, TypeError):
+            return None
+    return None
+
+
 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] = []
@@ -220,12 +240,15 @@ def fetch_issues_with_spent_time(
     to_date: str,
     user_id: Optional[Union[int, str]] = None,
     by_activity: bool = False,
+    dedup_before: Optional[datetime] = None,
 ) -> 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.
     If by_activity is True, returns per-activity breakdown as third tuple element.
+    If dedup_before is set, filters out time entries whose created_on AND updated_on
+    are both before dedup_before (AND logic: both must be < cutoff to exclude).
     Returns list of (issue, total_hours, activities) tuples.
     Raises RedmineAPIError on API/auth/network failures.
     """
@@ -238,14 +261,34 @@ def fetch_issues_with_spent_time(
             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
+        time_entries = list(
+            redmine.time_entry.filter(user_id=target_user_id, from_date=from_date, to_date=to_date)
         )
     except RedmineAPIError:
         raise
     except Exception as exc:
         raise RedmineAPIError(_format_redmine_error(exc), original=exc) from exc
 
+    # Дедупликация: отсекаем записи, которые были учтены в предыдущем отчёте.
+    # Запись исключается, если BOTH created_on AND updated_on < dedup_before.
+    # Записи без метаданных (created_on/updated_on == None) не фильтруются.
+    if dedup_before is not None:
+        filtered: list = []
+        for entry in time_entries:
+            created = _parse_datetime(getattr(entry, "created_on", None))
+            updated = _parse_datetime(getattr(entry, "updated_on", None))
+
+            if created is None and updated is None:
+                filtered.append(entry)
+            elif created is not None and updated is not None:
+                if created >= dedup_before and updated >= dedup_before:
+                    filtered.append(entry)
+            elif created is not None and created >= dedup_before:
+                filtered.append(entry)
+            elif updated is not None and updated >= dedup_before:
+                filtered.append(entry)
+        time_entries = filtered
+
     # Агрегируем часы по issue.id (и активности, если требуется)
     spent_time: Dict[int, float] = {}
     spent_by_activity: Dict[int, Dict[str, float]] = {}
@@ -278,7 +321,9 @@ def fetch_issues_with_spent_time(
     result = []
     for issue in issues:
         iid = issue.id
-        total_hours = spent_time.get(iid, 0.0)
+        if iid not in spent_time:
+            continue
+        total_hours = spent_time[iid]
         activity_breakdown = spent_by_activity.get(iid) if by_activity else None
         result.append((issue, total_hours, activity_breakdown))