Fix path references in scripts after reorganization

Update 8 scripts to use Path(__file__).parent.parent as PROJECT_ROOT
so they resolve data/, output/, and internet_cables/ relative to the
project root rather than the caller's working directory.

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

scripts/ingest_legiscan.py

@@ -51,7 +51,7 @@ import requests
 DB_NAME = "data_centers"
 API_KEY = os.environ.get("LEGISCAN_API_KEY")
 API_BASE = "https://api.legiscan.com/"
-CACHE_DIR = Path("data/legiscan_cache")
+CACHE_DIR = Path(__file__).parent.parent / "data" / "legiscan_cache"
 MIN_YEAR_DEFAULT = 2016
 RATE_LIMIT_DELAY = 0.5  # seconds between API calls