feat(user): report on another user's time entries

- Add user_id parameter to fetch_issues_with_spent_time().
- Support numeric ID, login, or full name resolution.
- Reject ambiguous names and unknown users with clear messages.
- Add CLI flags: --user-id, --user-login, --user-name.
- Only allow one user flag at a time.
- Add ResourceNotFoundError handling.
- Update README with usage examples.
- Add tests for user resolution and CLI flags.

Closes #40

redmine_reporter/cli.py

@@ -76,8 +76,29 @@ def main(argv: Optional[List[str]] = None) -> int:
         action="store_true",
         help="Print summary (total hours by project/version) to stderr",
     )
+    parser.add_argument(
+        "--user-id",
+        help="Redmine user ID for the report (default: current user)",
+    )
+    parser.add_argument(
+        "--user-login",
+        help="Redmine user login for the report (alternative to --user-id)",
+    )
+    parser.add_argument(
+        "--user-name",
+        help="Redmine user full name for the report (alternative to --user-id; ambiguous names are rejected)",
+    )
     args = parser.parse_args(argv)
 
+    # Валидация взаимоисключающих флагов пользователя
+    user_args = [args.user_id, args.user_login, args.user_name]
+    if sum(bool(a) for a in user_args) > 1:
+        print(
+            "❌ Specify only one of --user-id, --user-login, or --user-name.",
+            file=sys.stderr,
+        )
+        return 1
+
     # CLI-переопределения имеют приоритет над .env/env.
     if args.config:
         Config.load_config(args.config)
@@ -105,7 +126,11 @@ def main(argv: Optional[List[str]] = None) -> int:
         return 1
 
     try:
-        issue_hours = fetch_issues_with_spent_time(from_date, to_date)
+        issue_hours = fetch_issues_with_spent_time(
+            from_date,
+            to_date,
+            user_id=args.user_id or args.user_login or args.user_name,
+        )
     except RedmineAPIError as e:
         print(f"❌ {e.message}", file=sys.stderr)
         if args.debug and e.original is not None: