feat: status translation overrides via YAML config

report.status_translation in YAML config overrides/extends the builtin
STATUS_TRANSLATION dictionary; without the section behavior is unchanged.

- AppConfig.report_status_translation + _resolve_str_dict (warns and
  skips non-scalar values, resolves ${VAR} references)
- Config.get_status_translation() returns merged copy (lazy import,
  builtin dict never mutated)
- build_grouped_report() accepts optional status_translation parameter
- --init-config template gains commented example, docs/CONFIG.md updated

Closes #65

tests/test_report_builder.py

@@ -277,3 +277,27 @@ def test_group_rows_preserves_row_data():
 def test_group_rows_empty():
     """Пустой список — пустой словарь."""
     assert group_rows_by_project_and_version([]) == {}
+
+
+# -- #65: кастомный перевод статусов --
+
+
+def test_build_grouped_report_custom_status_translation():
+    """status_translation переопределяет встроенный словарь (#65)."""
+    issue = MockIssue("P", "S", "New", "v1.0", 1)
+    rows = build_grouped_report([(issue, 1.0)], status_translation={"New": "Новая"})
+    assert rows[0]["status_ru"] == "Новая"
+
+
+def test_build_grouped_report_custom_status_translation_passthrough():
+    """Статус вне кастомного словаря возвращается как есть (#65)."""
+    issue = MockIssue("P", "S", "Closed", "v1.0", 1)
+    rows = build_grouped_report([(issue, 1.0)], status_translation={"New": "Новая"})
+    assert rows[0]["status_ru"] == "Closed"
+
+
+def test_build_grouped_report_none_translation_uses_builtin():
+    """status_translation=None — используется встроенный словарь (#65)."""
+    issue = MockIssue("P", "S", "Closed", "v1.0", 1)
+    rows = build_grouped_report([(issue, 1.0)], status_translation=None)
+    assert rows[0]["status_ru"] == "Закрыто"