feat(generator): добавлено состояние версии 2 для рестартов

- Зачем:
  - генератор должен переживать рестарт без потери популяции пользователей и коротко прерванных активных визитов.
- Что:
  - добавлен компактный state v2 для популяции, активных визитов и остатка бюджета рождений.
  - сервис генератора переведён на единый тиковый поток с сохранением и восстановлением состояния.
  - добавлена безопасная деградация для старого state v1 и битого state v2.
  - покрыты короткий и долгий простой, reset состояния и валидация вложенного state.
- Проверка:
  - uv run --with-requirements generator/requirements.txt pytest generator/tests -q.
  - git diff --check.

generator/tests/test_service.py

@@ -2,11 +2,21 @@
 Тесты для GeneratorService и интеграционных сценариев.
 """
 
+import logging
+import random
+from dataclasses import replace
+from datetime import datetime, timezone
 from unittest.mock import MagicMock, patch
 
 import pytest
 from generator import (
-    Config, EventDictionary, GeneratorService, KafkaBatchHistory
+    Config,
+    EventDictionary,
+    EventGenerator,
+    GeneratorService,
+    GeneratorState,
+    KafkaBatchHistory,
+    TickStreamGenerator,
 )
 
 
@@ -90,3 +100,111 @@ class TestGeneratorServiceDisabled:
             service.start()
         
         assert "disabled" in caplog.text.lower() or "GEN_ENABLED" in caplog.text
+
+
+class TestGeneratorServiceStateV2:
+    """Тесты подключения state v2 к сервисному запуску."""
+
+    def test_start_restores_tick_stream_state_v2(self, base_config, event_dictionary):
+        """Сервис восстанавливает популяцию и активные визиты из state v2."""
+        source_generator = EventGenerator(event_dictionary, base_config)
+        source_stream = TickStreamGenerator(source_generator)
+        tick_at = datetime.now(timezone.utc).replace(tzinfo=None)
+        source_stream.generate_tick(event_budget=10, tick_started_at=tick_at)
+        state = source_stream.to_state(
+            tick=3,
+            rng_state=source_generator.rng.getstate(),
+            last_batch_id="batch-3",
+            last_timestamp=tick_at,
+        )
+
+        state_manager = MagicMock()
+        state_manager.load.return_value = state
+
+        with patch("clickstream_generator.service.start_http_server"), \
+             patch("clickstream_generator.service.ensure_topics"), \
+             patch("clickstream_generator.service.KafkaPublisher"), \
+             patch("clickstream_generator.service.KafkaBatchHistory"), \
+             patch(
+                 "clickstream_generator.service.KafkaStateManager",
+                 return_value=state_manager,
+             ), \
+             patch.object(GeneratorService, "_main_loop", return_value=None):
+
+            service = GeneratorService(base_config)
+            service.start()
+
+        assert service._tick == 3
+        assert service.stream.population_user_ids == source_stream.population_user_ids
+        assert service.stream.active_visit_count == source_stream.active_visit_count
+
+    def test_save_state_writes_tick_stream_state_v2(self, base_config):
+        """Сервис сохраняет v2-снимок тикового слоя."""
+        service = GeneratorService(base_config)
+        service.state_manager = MagicMock()
+        tick_at = datetime.now(timezone.utc).replace(tzinfo=None)
+        service.stream.generate_tick(event_budget=10, tick_started_at=tick_at)
+        service._tick = 1
+
+        service._save_state("batch-1")
+
+        saved_state = service.state_manager.save.call_args.args[0]
+        assert saved_state.version == "2.0"
+        assert saved_state.population
+        assert saved_state.active_visits
+        service.state_manager.flush.assert_called_once()
+
+    def test_state_reset_skips_loading_saved_state(self, base_config):
+        """GEN_STATE_RESET=true запускает сервис с чистого состояния."""
+        reset_config = replace(base_config, state_reset=True)
+        state_manager = MagicMock()
+
+        with patch("clickstream_generator.service.start_http_server"), \
+             patch("clickstream_generator.service.ensure_topics"), \
+             patch("clickstream_generator.service.KafkaPublisher"), \
+             patch("clickstream_generator.service.KafkaBatchHistory"), \
+             patch(
+                 "clickstream_generator.service.KafkaStateManager",
+                 return_value=state_manager,
+             ), \
+             patch.object(GeneratorService, "_main_loop", return_value=None):
+
+            service = GeneratorService(reset_config)
+            service.start()
+
+        state_manager.load.assert_not_called()
+        assert service._tick == 0
+
+    def test_invalid_restored_v2_state_starts_fresh(self, base_config, caplog):
+        """Сервис не падает, если v2 state ссылается на неизвестный профиль."""
+        state_manager = MagicMock()
+        state_manager.load.return_value = GeneratorState(
+            tick=9,
+            rng_state=random.Random(42).getstate(),
+            last_batch_id="bad-v2",
+            last_timestamp=datetime.now(timezone.utc),
+            population=[
+                {
+                    "user_domain_id": "user-unknown",
+                    "seed_click_id": "missing-click-id",
+                }
+            ],
+            active_visits=[],
+        )
+
+        with patch("clickstream_generator.service.start_http_server"), \
+             patch("clickstream_generator.service.ensure_topics"), \
+             patch("clickstream_generator.service.KafkaPublisher"), \
+             patch("clickstream_generator.service.KafkaBatchHistory"), \
+             patch(
+                 "clickstream_generator.service.KafkaStateManager",
+                 return_value=state_manager,
+             ), \
+             patch.object(GeneratorService, "_main_loop", return_value=None), \
+             caplog.at_level(logging.WARNING, logger="generator"):
+
+            service = GeneratorService(base_config)
+            service.start()
+
+        assert service._tick == 0
+        assert "State data was invalid" in caplog.text