fix(tooling): remove unused imports flagged by ruff

Drop unused hashlib, math, and os imports from assign-astro-ids,
generate-star-map, and test_quaternius_raw to pass ruff clean.

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

tooling/assign-astro-ids.py

@@ -17,7 +17,6 @@ Also writes spectral class from the real catalog into each node.
 """
 
 import json
-import hashlib
 from pathlib import Path
 
 STAR_MAP_PATH = Path(__file__).parent.parent / "docs/design/star-map.json"

tooling/generate-star-map.py

@@ -13,10 +13,8 @@ Standard library only. No external dependencies.
 from __future__ import annotations
 
 import json
-import math
 import random
 import sys
-import os
 import argparse
 from collections import defaultdict, deque
 from pathlib import Path

tooling/test_quaternius_raw.py

@@ -1,6 +1,5 @@
 """Load original Quaternius body + hair as-is and export a combined GLB for visual inspection."""
 import sys
-import os
 import bpy
 
 if __name__ == "__main__":