research(rectification): put scripts on the path before nadi imports (BUG-1240)

Running the study as a file does not put scripts/ on sys.path, so the
production chart imports failed before any scoring. The library inserts
that directory itself. No rule or threshold changed.

scripts/research/nadi_seconds_lib.py

@@ -21,12 +21,17 @@ from __future__ import annotations
 import hashlib
 import json
 import math
+import sys
 from collections.abc import Mapping, Sequence
 from datetime import date, datetime, timedelta
 from pathlib import Path
 from random import Random
 from typing import Any
 
+_SCRIPTS = str(Path(__file__).resolve().parents[1])
+if _SCRIPTS not in sys.path:
+    sys.path.insert(0, _SCRIPTS)
+
 import dasha_analyzer
 import divisional_charts_extended
 import domain_calculation_service