fix(extract): load .env automatically via load_dotenv()

PROXY_URLS_* and other secrets were defined in .env but never loaded,
causing availability to run in slow serial mode (1 req/s) instead of
parallel mode with proxies.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

extract/padelnomics_extract/src/padelnomics_extract/_shared.py

@@ -11,9 +11,12 @@ from datetime import UTC, datetime
 from pathlib import Path
 
 import niquests
+from dotenv import load_dotenv
 
 from .utils import end_run, open_state_db, start_run
 
+load_dotenv()
+
 LANDING_DIR = Path(os.environ.get("LANDING_DIR", "data/landing"))
 
 HTTP_TIMEOUT_SECONDS = 30