fix: CRITICAL - Correct HEAD A class mapping (class 0=REAL, 1=AI)

fix: Correct FFTFeatureExtractor method name (extract_features)

feat: Deploy SpectralDetector V3.6 Cascaded - 4-HEAD system (A/B/C/D) with temperature calibration

Fix: upgrade pickles to numpy 2.x, add pydantic 2.10.6, recreate meta-router, export demo at module level

Fix: add backward compatibility aliases for tau_* attributes

Initial deployment - SpectralDetector V3.5