feat: add fade effects with API control and real-time event subscription
test: add API integration tests with isolated test environment and coverage reporting
build: update Makefile for recursive source finding, dynamic linking, and test targets
docs: document abstraction layer, fade effects, and API enhancements in README
build: enhance security with stricter compiler flags and sanitizer build
refactor: replace standard memory functions with custom dwn_ variants
chore: remove unused wifi and dropdown menu code from systray
