feat: многопоточный парсинг + forum survey

- Throttle: Thread-safe координация задержек
- BanDetector: автоопределение бана
- fetch: thread-local сессии вместо глобальной
- run: ThreadPoolExecutor + диапазоны страниц + мерж
- output/state: поддержка worker-папок и merge_states()
- __main__: --workers, --no-delay, --no-ban-test
- VWTS/forums-survey.md: обзор 20+ автофорумов

vwts_scraper/state.py

@@ -1,8 +1,11 @@
 """Управление состоянием (state.json в папке раздела)."""
 
-import json
+import json, logging
+from pathlib import Path
 from .config import OUTPUT_DIR
 
+log = logging.getLogger(__name__)
+
 
 def _state_file(section_slug: str) -> Path:
     d = OUTPUT_DIR / section_slug
@@ -20,3 +23,26 @@ def load(section_slug: str) -> dict:
 def save(section_slug: str, st: dict):
     _state_file(section_slug).write_text(
         json.dumps(st, ensure_ascii=False, indent=2), encoding="utf-8")
+
+
+def merge_states(section_slug: str):
+    """Собрать состояния всех воркеров в единый state.json."""
+    root = OUTPUT_DIR / section_slug
+    merged = {"topics_done": {}, "pages_done": [], "file_index": 0, "topic_count": 0}
+
+    for wdir in sorted(root.glob("worker_*/state.json")):
+        try:
+            wst = json.loads(wdir.read_text(encoding="utf-8"))
+            merged["topics_done"].update(wst.get("topics_done", {}))
+            merged["pages_done"].extend(wst.get("pages_done", []))
+            merged["topic_count"] += wst.get("topic_count", 0)
+        except Exception as e:
+            log.warning(f"⚠️  Ошибка чтения {wdir}: {e}")
+
+    merged["pages_done"] = sorted(set(merged["pages_done"]))
+    merged["file_index"] = len(list(root.glob("part_*.jsonl"))) - 1
+    if merged["file_index"] < 0:
+        merged["file_index"] = 0
+
+    _state_file(section_slug).write_text(
+        json.dumps(merged, ensure_ascii=False, indent=2), encoding="utf-8")