refactor: modularize project structure and separate API from crawlers

- Introduce app/ package with config, services (storage, notifications), API server, and crawler modules
- Add BaseCrawler and BarronsCrawler; extract notifications and storage
- Keep enhanced_crawler.py as back-compat entry delegating to app.runner
- Add template crawler for future sites
- Update README with new structure and usage
- Extend .env.template with DATA_DIR/LOG_DIR options

app/services/storage.py

@@ -0,0 +1,23 @@
+import json
+import os
+from typing import Any, Dict
+
+
+def data_file_path(data_dir: str, name: str) -> str:
+    os.makedirs(data_dir, exist_ok=True)
+    return os.path.join(data_dir, name)
+
+
+def load_json(path: str) -> Dict[str, Any]:
+    try:
+        with open(path, 'r', encoding='utf-8') as f:
+            return json.load(f)
+    except FileNotFoundError:
+        return {'last_update': None, 'stock_picks': [], 'stats': {}}
+
+
+def save_json(path: str, data: Dict[str, Any]) -> None:
+    os.makedirs(os.path.dirname(path), exist_ok=True)
+    with open(path, 'w', encoding='utf-8') as f:
+        json.dump(data, f, ensure_ascii=False, indent=2)
+