fix(generator): исключено смешение миров при запуске

- Зачем:
  - старый state и ручной live-генератор могли тихо писать события в новый мир данных.
- Что:
  - добавлена общая проверка чистого стенда для Airflow и host-путей.
  - защищены backfill, import, continue и clean-start сценарии live-generator.
  - описан миграционный отказ старого state.
- Проверка:
  - make generator-test; docker compose config --quiet; py_compile; bash -n.

generator/src/clickstream_generator/service.py

@@ -31,6 +31,7 @@ from clickstream_generator.startup_history_artifact import (
     generation_settings_from_config,
     write_startup_history_artifact,
 )
+from clickstream_generator.state import UnsupportedStateVersionError
 
 
 logger = logging.getLogger("generator")
@@ -98,7 +99,21 @@ class GeneratorService:
                 return
 
             if not self.config.state_reset:
-                restored_state = self.state_manager.load()
+                try:
+                    restored_state = self.state_manager.load()
+                except UnsupportedStateVersionError as exc:
+                    logger.error(
+                        "Readable generator state uses an old format: version %s. "
+                        "Run make clean or set GEN_STATE_RESET=true only if you "
+                        "intentionally start a new world.",
+                        exc.found_version,
+                    )
+                    raise IncompatibleStateError(
+                        f"state version {exc.found_version} is not supported "
+                        f"by this code version ({exc.expected_version}); "
+                        "run make clean, or set GEN_STATE_RESET=true to start "
+                        "a new world intentionally"
+                    ) from exc
                 if restored_state:
                     try:
                         self.manifest_manager = KafkaStartupHistoryManifest(