- DEFAULT_JSON_SCHEMA: drop the 8 detector_* keys left over from the
removed detector_response module; CLI dry-run drops the dead
'Detector: not configured (Phase 4)' line
- CSV export: single-mode no longer writes branch_1_PhaseSpace /
branch_1_Radiative duplicates next to the bare PhaseSpace/Radiative
columns; per-branch core factors only in multi-branch mode
- Visualizer: debug panels fall back to the unprefixed core-factor
columns for single-mode CSVs instead of skipping them
- Spectrum ylabel now states the actual units: normalized spectrum
[MeV^-1], not 'Normalized Counts / keV'
- tests: defaults assert detector keys gone; column layout pinned for
single vs multi; panel and ylabel assertions
unzhakov