First-time run of ruff-format via pre-commit hook normalises quote
style, trailing commas, and whitespace across 188 Python files.
No logic changes.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Implements lazy-cached load_signals() and pure match_signals() with
frequency/bandwidth/modulation/region scoring for the signal ID feature.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>