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
feat: enhance alt-tab selection with bold font rendering
refactor: simplify title bar color logic to use focused/unfocused states
perf: increase focus animation duration for smoother transitions
refactor: update build dependencies for decorations and workspace modules
