refactor(ecg): migrate feature extraction to vector-based pipeline and remove...
refactor(ecg): migrate feature extraction to vector-based pipeline and remove legacy EcgSignal module
- Replace raw array/pointer handling with std::vector-driven data flow across ECG modules
- Remove deprecated EcgSignal implementation and associated build references
- Consolidate denoising logic under EcgDenoise for unified processing pipeline
- Improve modular separation between acquisition, filtering, and feature extraction layers
- Enhance maintainability and memory safety by eliminating legacy ownership patterns