Add retry/backoff, timeout, and issue_id chunking to Redmine client

- #24: Mount HTTPAdapter with Retry(total=3, backoff_factor=0.5) for
  HTTP 429/500/502/503/504 on the Redmine session, set 30s timeout
- #21: Split large issue_id lists into chunks of 100 to avoid exceeding
  URL length limits on reverse proxies

Closes #24, #21

tests/test_client.py

@@ -133,7 +133,7 @@ def test_fetch_uses_api_key_when_present(mock_redmine_class):
 
     _, kwargs = mock_redmine_class.call_args
     assert kwargs["key"] == "api-token"
-    assert kwargs["requests"] == {"verify": DEFAULT_REDMINE_VERIFY}
+    assert kwargs["requests"]["verify"] == DEFAULT_REDMINE_VERIFY
     assert "username" not in kwargs
     assert "password" not in kwargs
 
@@ -151,7 +151,7 @@ def test_fetch_uses_username_password_when_no_api_key(mock_redmine_class):
     _, kwargs = mock_redmine_class.call_args
     assert kwargs["username"] == "user"
     assert kwargs["password"] == "password"
-    assert kwargs["requests"] == {"verify": DEFAULT_REDMINE_VERIFY}
+    assert kwargs["requests"]["verify"] == DEFAULT_REDMINE_VERIFY
     assert "key" not in kwargs
 
 
@@ -165,4 +165,88 @@ def test_fetch_uses_custom_verify_path(mock_redmine_class):
     fetch_issues_with_spent_time("2026-01-01", "2026-01-31")
 
     _, kwargs = mock_redmine_class.call_args
-    assert kwargs["requests"] == {"verify": "/tmp/redmine-ca.pem"}
+    assert kwargs["requests"]["verify"] == "/tmp/redmine-ca.pem"
+
+
+# -- #24: Таймаут и retry --
+
+
+@mock.patch.dict(os.environ, PASSWORD_ENV, clear=True)
+@mock.patch("redmine_reporter.client.Redmine")
+def test_fetch_sets_timeout_in_requests(mock_redmine_class):
+    """В requests dict передаётся timeout (#24)."""
+    mock_redmine = mock_redmine_class.return_value
+    _configure_current_user(mock_redmine)
+    mock_redmine.time_entry.filter.return_value = []
+
+    fetch_issues_with_spent_time("2026-01-01", "2026-01-31")
+
+    _, kwargs = mock_redmine_class.call_args
+    assert "timeout" in kwargs["requests"]
+    assert kwargs["requests"]["timeout"] == 30
+
+
+@mock.patch.dict(os.environ, PASSWORD_ENV, clear=True)
+@mock.patch("redmine_reporter.client.Redmine")
+def test_fetch_mounts_retry_adapter(mock_redmine_class):
+    """На сессию монтируется HTTPAdapter с retry для временных ошибок (#24)."""
+    mock_redmine = mock_redmine_class.return_value
+    _configure_current_user(mock_redmine)
+    mock_redmine.time_entry.filter.return_value = []
+
+    fetch_issues_with_spent_time("2026-01-01", "2026-01-31")
+
+    # Проверяем, что session.mount был вызван для http:// и https://
+    mount_calls = mock_redmine.session.mount.call_args_list
+    prefixes = [call.args[0] for call in mount_calls]
+    assert "https://" in prefixes
+    assert "http://" in prefixes
+
+    # Проверяем retry-конфигурацию адаптера
+    https_adapter = next(
+        call.args[1] for call in mount_calls if call.args[0] == "https://"
+    )
+    max_retries = https_adapter.max_retries
+    assert max_retries.total == 3
+    assert 429 in max_retries.status_forcelist
+
+
+# -- #21: Чанкирование issue_ids --
+
+
+@mock.patch.dict(os.environ, PASSWORD_ENV, clear=True)
+@mock.patch("redmine_reporter.client.Redmine")
+def test_fetch_chunks_large_issue_count(mock_redmine_class):
+    """При >100 задач запросы разбиваются на чанки (#21)."""
+    mock_redmine = mock_redmine_class.return_value
+    _configure_current_user(mock_redmine)
+
+    # 250 time entries → 250 уникальных issue_id
+    entries = []
+    for i in range(1, 251):
+        e = mock.MagicMock()
+        e.issue.id = i
+        e.hours = 1.0
+        entries.append(e)
+    mock_redmine.time_entry.filter.return_value = entries
+
+    # issue.filter вызывается с чанками по 100 ID
+    call_chunks = []
+
+    def issue_filter_side_effect(**kwargs):
+        ids_str = kwargs.get("issue_id", "")
+        call_chunks.append(ids_str)
+        ids = [int(x) for x in ids_str.split(",")]
+        return [mock.MagicMock(id=i, project="P", subject="T", status="New") for i in ids]
+
+    mock_redmine.issue.filter.side_effect = issue_filter_side_effect
+
+    result = fetch_issues_with_spent_time("2026-01-01", "2026-01-31")
+
+    # Должно быть 3 вызова (100 + 100 + 50)
+    assert len(call_chunks) == 3
+    assert len(call_chunks[0].split(",")) == 100
+    assert len(call_chunks[1].split(",")) == 100
+    assert len(call_chunks[2].split(",")) == 50
+    assert result is not None
+    assert len(result) == 250